I have been following this site for over a year and this is my first post. Before I begin, I would just like to say there is no way I would be even close to how far along I have come to bringing this boat back to life without all of the great technical advice I have read on this site. Not to mention the humor and inspiration of other member's much greater projects to keep me motivated, so thanks again.

So, this where I am at. I have a 1986 Ski Nautique with a 351W Commander package. I had been storing the boat for a family friend for a number of years, but it sat due to mechanical issues but reportedly ran great at one time. They ended up leaving the state and I became the new owner and I have been working on it ever since. I feel I am very close experiencing the boats full performance, but I am stumped with some final acceleration issues and could use some advice.

Acceleration problem #1: On the water under load, when I give it throttle from idle it stumbles and dies. I does much better in reverse as there is not as much load as I have read. I can increase the idle and throttle my way through/around it but the high idle makes it tricky around the docks and is not a long-term solution and can't be great for the transmission. There was a previous post "Stalling in forward" that was very similar, but there was no solution posted. I have also followed the posted advice on setting the throttle cable linkage correctly as well.  

Acceleration problem #2: On the water under load at about 2700 rpm, additional throttle does not increase RPM/speed. Which feels to me as if the secondaries are not opening. However, that is based only on what I suspect on what I have read. I have not had the opportunity to physically observe that this is the case as the GF has not yet agreed to help me check this on open water under load. Since she had to help me push this boat after it has died on the water once or twice already, I'm giving her a little room this one.  

Seems to run great once past the stall attempt from idle and to the 2700 or so rpms.

The following is based on what I have done, and some based on what my boat mechanic has advised. I will try to limit what was done in regard to acceleration issues.

Compression test was good (can provided numbers if needed).

Leak down test was good.

Holley 4160 Carburetor was rebuilt by mechanic.

Holley wedge plate was installed/all new gaskets by mechanic but not skidim gaskets as I have seen suggested.

All new fuel filters and all new fuel.

DUI conversion done by mechanic. New wires, new plugs (no fouling), wiring order triple checked.

Timing set to 12 degrees BTDC

Manifold bolts tightened to spec. 

Electric choke adjusted and verified that it is fully open when warm.

Vacuum leaks checked around base of carb and manifold. (3/4 can of carb cleaner and 1/2 bottle propane)

-It doesn't mean it's not there, but I haven't found one.

-Vacuum gauge from back of carburetor to the PCV (Not on a T but directly from the PCV hose) shows a steady 15-16 lbs.    vacuum. It is my understanding it should be showing 19-22. 

Other possible indicators:

At idle (no throttle at all) seems fine from when its first started and idling at the boat launch. When I come off throttle to idle after a run (at a whopping 2700 rpms ) the idle hangs high (1000 rpms or so). When the engine cools after sitting, the idle drops back down. Also, both cold and hot starts need a pump of the accelerator to start. Cold start needs three pumps and throttle left open 1/3. Hot starts need one pump. Finally, the idle mixture screws seem happiest at about 3-3.5 rotations out (based on my vacuum test). 

My thoughts are a vacuum leak, but I can't find one and I could also be completely wrong. I have attached a photo of the engine if anyone sees anything obvious that may be related or not that needs addressing (and to see if I could post a photo correctly).  Any advice would be greatly appreciated. I hope I have described this somewhat clearly and look forward to being part of this great community. 

Your timing is at 12 degrees BTDC at idle speed, what is it a 3500 rpm revving it in neutral. It should get there easily in neutral with no load on the engine and the timing should end up at somewhere between 32 and 36 degrees.

Your vacuum reading of a steady 15 to 16 sounds OK.

What do you have for a prop on the boat? it would take a way oversized prop to keep RPMs that low but it's worth asking the question

If you're only getting to 2700 RPMs your secondaries won't open due to not enough air flow down the venturis.to create the vacuum signal that opens them. (it's not engine vacuum)

If everything was good, and the secondaries weren't opening you'd only be down a few hundred RPM from a normal of about 44 to 4500 ish and be down a few MPH also.

3 to 3.5 turns out on the idle mixture screws would be telling me you have some restricted/dirty passages in the idle circuit.

Good job getting a picture posted in your first post.

Ok, so that was more than a couple of things  

And in true Colunbo fashion......................just one more thing, when you're at 2700 RPM, how fast is the boat going ?

Thank you for reply. I really appreciate it.

1. On the trailer in neutral, the timing at 3000 rpms is at 24 degrees. This from my mechanics notes when the DUI conversion was done. I can check it again myself and get it up to 3500 rpms and check it there as well if that would help. I should also note that the distributor that I replaced was a motorcraft automotive distributor, so it must have had distributor issues in the past. 

2. The prop markings are "7 85 FEDERAL NI-BRAL CUP 13RH13".

3. Your explanation of only getting to 2700 rpms not being enough to create the vacuum signal makes a lot of sense versus engine vacuum. I guess I should also mention that I replaced the secondary spring to one lighter in hopes for a solution but there was no change which again supports your point. 

4. Regarding dirty passages in idle circuit. I know very little about the internal parts of the carburetor, so I have left that to the experts.  I've had the carb rebuilt twice now by reputable shops, once when I first got the boat about a year and half ago to at least get it running and then again recently when the DUI conversion was done when the mechanic noticed excessive fuel delivery. I would hope it's clean by now, but I'm not ruling anything out with this boat at this point.

5. Only one of the speedometers is working at this point (I can't wait to be able to work on those things whenever I get past these issues). However, it appears to track the RPMs fairly close to 1:1. 2700 rpms is showing close to 27 mph.

Hopefully this helps, please let me know what you think. 

Thanks

 

There should be about 30 to 34 degrees advance at 3500 RPM. You should have 20 to 24 degrees of mechanical advance on top of your initial idle setting  .

DUI says 24 degrees of mechanical advance from the flyweights and springs that are installed. People seem to see between 20 and 24, but that's still a lot more than what looks like 14 degrees of mechanical advance that you have now.

The prop is right for the boat and the speed vs RPM correlation is right.

It does sound like your carb still has some issues but the first thing I would verify is your throttle cable connection.   Make sure when you open the throttle from the driver seat it actually does open the throttle at the carburetor.   You would need to remove the spark arrestor, Engine turned off, open the throttle full and look down the carb to see how far the butterfly's are open.  You will probably need to open the choke first by hand to see what the butterfly's below the choke are doing.  This will verify your Primary, (front 2 barrels of your 4 bbl carb) are doing.   If they are not straight up and down with your throttle wide open it can be adjusted to fix it.   This is a simple 5 minute check to do before getting into complicated stuff.   

Nice work so far.

Mark

If you set the linkage correctly, hopefully you checked for full opening of the primary butterflies, but if you didn't then MrMcD's suggestion would be the next thing to check.

It would be a nice easy fix

I am optimistic that the total timing issue will be confirmed (confirmed as a problem).  I will definitely get those results posted soon. 

I followed a previous post awhile back that described advancing the throttle forward to the detent and then attaching the other end of the throttle cable to the carburetor at that point. The explanation I read (to include the neutral position for the transmission) was much better than mine, but it seemed to get me extremely close to what I think feels right (or close to right) on the linkage. 

Thank you for the recommendation on checking the primary butterflies at WOT. This is something I had not done. I just checked and the primary butterflies are both fully open at WOT. Anything we can check off the list is a win. Thanks.

Thank you for the tip. I will definitely get that downloaded. I am hoping that when the top end issue is resolved on this boat that it will take off like a rocket and break the one working speedometer needle. I'm kidding (half kidding).  

At idle which is about 750 RPM the initial timing is set at 12 degrees BTDC. Idle under 750 RPMs seems like it wants to try and stall, so that's where I have kept it. At 2000 RPM the timing is about 22 degrees and at 3500 RPM the timing is in the mid 30's. It is hard to tell the exact number as it was bouncing around a bit, but my best estimate would be about 35 degrees. At 3000 RPM it made a few popping noises, not backfiring though, and then smoothed out. That engine has not been run at those RPMs in quite some time. Sounded great once it smoothed out though.

I can only assume my mechanics notes regarding timing at 24 degrees at 3000 RPM were somehow inaccurate. However, these are the numbers I am seeing, which seems more in line with what they should be based on the recommendations. Any thoughts?

Your mechanic might have been saying you had 24 degrees of mechanical advance, not total.  Just a guess.

In your list of things done you mention new fuel filters and new fuel.  Has the fuel pump pressure been looked at?

I have gone through from the tank, pick up tube (that's what I called it), anti-siphon valve and everything was cleaned. I replaced the filter at the fuel pump, bought and installed a NOS fuel filter/water separator (orange cannister style). I have not checked the fuel pump pressure. I believe the vacuum gauge I purchased to check the vacuum at the carb also can be used to check fuel pressure. It does appear to me to be the original fuel pump, but that is only an assumption on my part. Any suggestions on the best way to check the fuel pressure since I have never done it?  Any advice would be appreciated. Thanks

There may be enough fuel in your carb bowl to run for almost a minute and do this test without hooking up an alternate fuel source.   You just want to see a constant flow of fuel and it should increase in flow if you bump the RPM up a little.   OBVIOUSLY extreme care needs to be taken or you can start a fire and burn up your boat.  Having a fire extinguisher handy is better than a good idea.  

Here is a photo of the fuel pump that is on it now just for reference. Not sure why the photo appears sideways.

Your ruptured diaphragm overflow tube must come out the backside of the pump and is camera shy in the picture. In your first post you can see the tube hooked to the flame arrestor

I haven't tested the fuel flow or fuel pressure yet but I wanted to respond your post. I did replace the the filter in the bottom of the fuel pump awhile back. The ruptured diaphragm overflow tube (a new part name for me) does connect to the back/top of the fuel pump.

Homework Question: The boat seems like it will run all day up to 2500-2700 RPM with no issues (once past the stall issue from idle discussed). When I try to give it more throttle beyond that (even to WOT) it just makes a sound like when you are at the doctors office and they tell you to say "Ahhhhhhh." I know that is likely the least technical way to describe it, but that's what it sounds like to my untrained ear. It doesn't speed up and it doesn't slow down. It doesn't really spit or sputter and it doesn't lose RPMs. Pull the throttle back to 2500-2700, the "Ahhhhhh" goes away and the boat drives on. 

I will test the fuel flow and fuel pressure and post it soon. It's going to be 114 degrees here today, but I am motivating myself to get it done this weekend. 

I have attached a photo of the other side of the engine for reference.  Thanks!

MrMcD wrote: Any chance the floats are just adjusted to low and it is running out of fuel?

Certainly seems like a fuel problem to me, since total advance has been confirmed.

One other item to mention - when I first got my '98 it ran well but would bog when running over 3,500 or so rpm.  It was pretty much ok for skiing but any more throttle and it would bog and surge.  Had a hard time figuring it out, a mechanic determined it was a collapsing fuel line, replaced the fuel hose to the tank, problem was solved.  Pretty much same symptoms as a partially failed anti-siphon valve but turned out it was the hose, not the valve.

The fuel flow at idle appears to be putting out a good amount of fuel, especially for being at idle (but that is my novice opinion). I would say it would be in line with the 1/4 gallon at a 30 second run as suggested. I did not actually time it out to 30 seconds as I was doing this project by myself and dealing with fuel I was trying error on the side of caution with everything going on. However, it was not a completely steady flow at idle. I attached a rubber fuel line to the end of the fuel line that attaches to the carburetor and then ran that line into a gas can. When I observed the fuel flowing into the can it was pulsing a bit as if in sync with the pump. There were no breaks in the fuel delivery but you could definitely feel the fuel pump working in the rubber fuel line. I am not sure if this is to be expected (seems logical though) since I have never tested fuel flow before. 

The fuel pressure was at 6 and I tested this a couple of times. I also checked the fuel lines from the carburetor all the way back to the tank for any binds or collapses and everything looked good. 

In dealing with this fuel line again after awhile (one of the first things I tackled over a year ago), I now recall when I cleaned the pickup tube and anti-siphon valve (not knowing what it was called then), the valve did not appear to have a ball or any other part in it, if I recall correctly. I wasn't sure at the time if it was just how the fitting was made or not so I just cleaned it and moved on. Now that I am a bit wiser (and I do mean a bit) that issue needs to re-addressed. In reading today, its a huge safety issue as well so I will put it on top of my list to find a new one. Although, I know the line/valve was cleaned and not obstructed. 

Below is a photo of what I am referring to when I say anti-siphon valve for clarity (assuming I'm correct).

Would the unobstructed anti-siphon valve cause any of the symptoms? Perhaps a reason for needing some throttle to start hot and cold? Any thoughts on the fuel flow, fuel pressure or are we headed to the carburetor? Anymore homework assignments?

Thanks for everyone guidance, I really do appreciate it!

Edit, the bowl might refill just in the time it takes from when you turn off the key till the engine actually stops but I am trying to find a way to check without tearing apart your carb.   Assuming your carb does not have external float adjustments or the side sight window?

There I was sittin' on the can after supper, thinking about your issue and suddenly it hit me...............constipation.

No not me, but maybe your boat is constipated .

How could that be you might wonder

If you have a restricted exhaust, it'll limit how much air the engine can draw in and get rid of out the exhaust which will limit how much power it can make, which will limit your top speed and acceleration because the prop is too much for the reduced power output and you get that sound you described..

Easy for me to say from 2500 or so miles away, but I think you should at least check your exhaust hoses and mufflers for restriction. Hoses can collapse internally from excess heat like an overheat in the boats past or just plain get old and start coming apart.

The mufflers have some built in restriction from baffles, but a broken baffle lodged in the wrong spot can have a big effect on backpressure and power.

It's not the easiest thing to do wrestling with those wire reinforced hoses and having to be kinda delicate where the hose clamps to the fiberglass muffler so you don't break the muffler but since you're kinda at a loss for what to do it's probably worth a look at least.

It kinda like having a restricted catalytic converter or muffler in your car.

I think lots of extra air through the secondaries and no extra gas would make for a real lean engine that wouldn't want to maintain speed and probably just die

Your constipation hypothesis carries a lot of weight.  All kidding aside, it does make a lot of sense with the known history of this boat. I know the previous owner did replace one of the exhaust tubes from the manifold back to the transom due to failure. I would suspect an overheating issue at some point as you described. I know the previous owner also experienced an impeller that came apart as well and was replaced. 

After I took on the boat years later and got it running, I took it out for a test on the water and made it about 50 yards out from the no wake zone and the engine began to run hot quickly and I shut it down. Which takes us back to me and my GF pushing it back to the dock. Still haven't lived that one down.

In any event, it was another impeller that came apart. I then proceeded to remove all of the impeller pieces I could find from the inlet on the raw water pump (where a lot were smashed into), the thermostat housing and the hoses from the thermostat housing to the exhaust manifolds. This is where I stopped. I recall looking into the manifolds from the inlet side (which was pretty small) and really couldn't see much. 

So I am assuming I need to remove the exhaust tubes from the ends of the manifolds and check the exhaust tubes for any obstructions and see what I find inside the manifolds from the exhaust end? I can only image how fun removing the exhaust tubes from the manifolds will be, but I will be careful with the manifolds. This may take a bit for me to get done but I will update as I move along. 

If this is the solution, I might have a new name for this boat.

The collapsible exhaust tube explanation makes a lot of sense, especially with the known issues of the two failed impellers and one failed exhaust tube. Pretty ingenious safety feature for an exhaust hose and great information to know and share. I told myself I wasn't going to work on the boat today but I couldn't resist inspecting the exhaust tubes from the exhaust flap forward. Both exhaust tubes are clear all the way up to the point where they bend up to connect to the manifolds. After the bend to the connection at the manifold is not visible. 

Also, when the impeller came apart on me and I spent the time to try and find all the pieces I was concerned that perhaps some of it made it to the manifolds. After reconnecting everything, I recall using an infrared temp gauge to check both manifolds to see if either one was running hotter than the other. Both were running at equal temps +/- a few degrees, so I assumed they were good. However, the flip side is they could be equally clogged. I'm not looking forward to removing the exhaust tubes and inspecting the manifolds but that will be next unless this information is helpful enough. 

I'd be checking everything after the manifold outlets to be clear and unrestricted especially the parts where there' are sharp bends in the rubber that you haven't looked at yet.

If you have mufflers you'll see some restriction baffles but it sounds like maybe they were removed at some time.

Here's an old thread about "collapsible hose" in the link

2 baffles per muffler is normal and what you have in the picture looks normal for the rear baffle.

Good luck with the hoses.

My novice experience leads me to suspect that is time to return to the carburetor again after two previous shop rebuilds. The good news is we have checked a lot off the list (at least in my opinion) and I have learned a ton. We have to be getting close to a solution. Any other suggestions, advice or homework assignments? Thanks again for all the help, I really appreciate it.

I can't think of anyone locally who would have a spare and trustworthy 4160 carburetor, and after a couple shop rebuilds now, I'm thinking a new replacement is my best long term solution at this point. It will at least give me a spare that perhaps I can become more familiar with the internal workings at some point and have my own trustworthy replacement. 

It should also be noted that in my previous post regarding a possible carburetor replacement that it is NOT "Quality Fuel Technologies", it is "Quick Fuel Technology." That was my error and I just wanted to clarify for anyone lacking carburetor knowledge like myself who made read this in the future. 

Any other suggestions before I pull the trigger on the QFT M-600 would be greatly appreciated, to include support for the swap if you believe this is correct path as well. Thanks

I have had 2 quick fuels (2 different boats) and they have be hassle free.

 

You could use rubber or metal.

Rubber should be USCG approved line 

You can get a Sierra 18-8115 USCG rubber line that'll fit from a variety of places or make your own with USCG A-15 or A-10 approved hose and the right barbed fittings or bend your own metal line.

Your present line looks like somebody took a length of pre flared brake line and bent it to fit maybe. it has a little extra length to it.

Nothing wrong with what's there but it probably won't reach the bowl mounting location on the QF if you start bending it to fit.

And you may need a new flame arrestor or some dainty hammer work to let the one you have clear the external float adjusters that stick up to far to allow your arrestor to seat properly on the carburetor. The dainty hammer work would be indenting the bottom enough to clear the adjusters .............or finding a short spacer to go between the carburetor and the arrestor.

Yours looks like it might be small enough in diameter that it'll fit without interference.

Thank you as well KENO for pointing me in the right direction regarding the fuel line and providing the part number. A new carburetor without a fuel line that fits wouldn't do me much good. Ha. I will get that Sierra fuel line ordered as well. 

I also thought I read an earlier post about a spacer that was available for the QF conversion. If I find it I will post that part number again here as well. Hopefully I wont need it if my arrestor is small enough, but inevitably I'm sure I will.

Thanks again for all the guidance in getting this far!  I will get the orders in this weekend and update soon with the new QF installed. For those of you with smooth running boats, enjoy the weekend!

The distributor was installed by the mechanic so that is something I can check. I read through the instructions from Performance Distributors and it clearly states "do not over tighten" the 2 nylon rotor hold down screws. In determining if they were over tightened, should the rotor (or something else) do or not do something if they are in fact over tightened? Also the initial timing was set and confirmed at 12* and the total timing was confirmed at about 35*. Not sure if those timing numbers would exclude a possible over tightening problem but I just thought I would mention in case it did. Thanks

Yup.  If the timing advance curve is working as it should, then the timing advance mechanism in the DUI was not over-tightened.  Uncle Buck referred to this situation when he originally installed the DUI on his engine.  The timing advance was inoperable.  The timing stayed at 10 degrees BTDC.  As soon as I loosened the nylon bolts inside the DUI so that the advance mechanism moved freely, the timing advance mechanism worked as advertised.

JQ

There's gotta be some more to the story of what Buck did and you fixed to make his advance work.

I decided I'd pull out a parts DUI distributor yesterday and duplicate this overtightening feat to bind up the advance mechanism.

I tried everything I could considering my general wimpiness, and all that happened was nothing,............the advance worked fine, but I was strong enough to break a screw .

So.............I fire off an e mail to the DUI guys, get an answer this morning and the precaution about overtightening is to keep from breaking the nylon screws and nothing to do with binding up the advance mechanism. They use nylon to prevent arcing.

Looking at where the screws go in relation to the advance mechanism, it's just not possible

Something on the advance mechanism didn't look quite right, so I removed the nylon screws and did a quick inspection of the dizzy.  After poking around a bit, I was able to get the advance mechanism to freely rotate without issues.   Then I re-installed the nylon screws...not too tight.  Everything worked as it should.  Cap back on and the engine fired up and the advance curve was spot on.

At the time, my assumption was that the nylon screws had somehow impeded the advance mechanism from rotating.  Perhaps my poking around a bit somehow freed-up whatever was binding-up the advance mechanism.  As the dizzy worked as advertised, we buttoned-up everything up and I didn't give much more thought to the nylon screws.  Go figure...

JQ

 

I did want to share a few things in getting it installed that may help others in the future who decide to go the QF route. If you are using the Holley 12 degree wedge under your QF, the 3.50" carburetor studs in the rear worked perfect for me. The mechanic had used bolts (not sure why) in the rear with the 4160 which will not work with the QF as there is not enough clearance to insert a bolt on one side. 

The spark arrestor just barely hit the float adjustment hardware on the top of the QF so I decided to go the spacer route. JQ has a previous post with a B&B Air Cleaner Sure Seal 1.50" spacer and another one from K&N which got me looking and I found a few others. Sorry, I need to review how to post a link or quote some ones previous post. In any event, I also found a Stef's Fabrication 72255 B&B Performance Air Cleaner Sure Seal 1" spacer that should be here today. I know its only a 1/2" shorter but it looked like the clearance was going to be close. After I ordered it I also found a 1/2" spacer on the Holley/QF site made by Mr. Gasket. So just a few options if clearance may be a concern.

I just want to thank everyone again for all the help. I hope to get the boat on the lake in the next week or so and give it run under load and see how it does. I am very optimistic and I will update as soon as I do. Thanks again. 

New carb ran great on the trailer. Easy starts and restarts so I was hoping for the same at the lake. Backed the boat down the ramp into the water and it would not start. The look from the GF was not one of confidence. It acted like it was starving for fuel. After about ten minutes of breaks and multiple attempts with multiple throttle pumps each time it finally started and idled great.

The Good: Once launched, it shifted into gear with no hesitation or stumble at all which was one of the previous issues. It was extremely smooth and it was great! Throttled up past the no wake zone which was smooth all the way to WOT. The Ahhhh sound on the high end had disappeared. However, when I looked down, the RPMs still remained at 2700 and the speedometer showed about 30. The Ahhhh was gone but the top end speed remained about the same. So we were content with that for the day. Cruised around awhile and the low end issues were gone and found a spot to anchor for a bit. Started back up after awhile and low end issues were ok but not as quite as good as it was before shutting down for a bit. 

The Bad: After starting back up and idling out we cruised for a bit at maybe half throttle and then I opened it up to WOT, there was a pop which sounded like it came from the carb and it died. GF look number 2. After multiple attempts to restart, it sounded like it wasn't getting any fuel. A passing boat was nice enough to tow us to a cove away from the rocks so we could anchor up and call in for a tow. Which of course took two hours to arrive. GF long two hour look number 3. While waiting I could see that there was no fuel in the primary float window. 

The Ugly:

 

The long tow back to the dock. I told her it runs great as long as we are being towed.  Yup, you guessed it...GF look number 4.

After contemplating this from yesterday until now my thoughts are it has to be the fuel pump. The pump is definitely older if not original. It is also about the only thing that hasn't been replaced in the fuel system. So I decided to go out this am and turn the engine over a few times and see if I could get/see fuel in the primary window. There was none. I adjusted the float level on the primary float to raise the float and no change so I returned it to the original position. I disconnect the fuel line from the carb and turned the engine over a few times to see if fuel was being delivered and fuel pumped out into the can at the same rate when the fuel pressure and fuel flow was tested earlier in this post. I am so confused.

 

I am going to order a new fuel pump no matter what based on its age but I am confused.  Why is there no fuel in the primary bowl on a brand new carburetor that was running fine (other than full top end), then dies, and the fuel pump seems to be delivering fuel? Am I lucky enough to get the one QF carb with issues? I also don't want to be tinkering around inside a brand new carb with no experience of rebuilding carburetors especially with what the new QF cost. Thoughts?

Additionally, any recommendations on a new fuel pump for this 351W. The one that is on it is a Carter with the internal filter. The new Carter pumps didn't have the best reviews. Is a pump with the internal filter necessary since it also has the fuel/water separator filter as well? 

Thanks

JQ

http://www.ebay.com/itm/264648307473" rel="nofollow - link     EBAY

The ruptured diaphragm connection is on the rear of the pump instead of the front and on your Commander that's a good thing because the front connection can need modification to clear the back of the raw water pump, depending on the pump.

It probably looks pretty much just like a copy of your present pump.

It's from "the Far East", he's put maybe 50 hours on it and so far so good

I was able to get the fuel pressure check done this am as well. Initially there was none while cranking and then it jumped to 6 psi. I tried it again and about the same. So I re-attached the fuel line and cranked it (I didn't crank it last time I raised and returned the float after I got home) a bit and it looked like some fuel in the primary bowl. I adjusted the float bowl up a bit and fuel level is back right in the middle of the window. When I tried this exact same thing at the lake after it died it did not produce the same result as it did today. In my novice opinion, it has to be a failing fuel pump. If we are correct it may also explain the hard start at the dock and loss of power at the top end (the only issue left after the fuel pump). Keeping in mind that I was the one stranded on the water for two hours so my opinion doesn't carry a lot of weight. 

This seems like really good news to me since I was really hoping to rule out the new carb. Any thoughts while I wait for the new fuel pump?

I've gotten some stuff from the Ebay seller referenced above and been plenty happy (along with 99.7 percent of his customers)

 

In anticipation of receiving the new fuel pump I went ahead and removed the old fuel pump. When pulling out the pump what also followed where a number of pieces as you can see below. 

The first two pieces next to the fuel pump are parts of the spring which are obviously broken. After close inspection, it appears that these two pieces have been broken for quite sometime and not just recently. I am assuming that the third piece is part of the pump assembly that would have ridden on the spring. 

Now, the fourth piece (far right) does not appear to have anything to do with the fuel pump and I think I know where it may have come from. When I removed the original distributor way back before beginning this post (before installing DUI distributor) I noticed that one of the teeth on the distributor gear was chipped. This looks like a perfect puzzle piece fit for that old chip. Could be wrong but it sure looks like it. 

I have just a couple quick questions. Would a fuel pump with a broken spring even pump (because apparently this one did at least a bit)? Also, it appears that when installing the new pump that the pump lever rests under the cam that can be seen through the port for the fuel pump, is that correct? It doesn't ride under a lifter/rod like in a Chevrolet, or am I not seeing the lifter/rod? Do I need to grease the new pump lever at all or will the engine oil take care of that? I know my technical terms may be off but hopefully I'm close enough to make sense.

The new fuel pump has arrived so I should be able to get it installed soon and report back. Hopefully after now finding something physically wrong/broken a final solution has been found. Although at this point I will believe it when I see it on the water under load and not requiring a tow.

Thank you again for everyone's help, I really appreciate it. 

JQ

Piece 3 falls out when the spring breaks, and there's another internal spring that keeps the pump somewhat working.

If you want to exert maximum effort putting the pump in, then rotate the engine CCW with Jonny's big wrench so #1 is at TDC on the compression stroke, but if you want to make it easier, rotate the engine one full turn after that and #1 will then be at TDC on it's exhaust stroke and the eccentric exerts the least amount of force on the pump arm so installation is easier. Like you said, the arm goes under the eccentric.

And............. it's nothing like the Chevy pushrod setup

if she's internet camera shy, just borrow some picture of someone  from somewhere on the internet  

So I was able to get the new fuel pump installed. I began to fight it for a few minutes and then thought it best to follow the advice above about rotating the engine which was way easier and great advice. 

Then it was time AGAIN to test it on the trailer. The primary bowl showed 1/2 way in the window and I was expecting success at last. I cranked it a number of times and no sign of it firing at all. I pulled the arrestor and fuel was dripping pretty heavy in the primaries. I checked the float level again and it was now completely full past the upper window (so I assume the new pump is working). I adjusted the bowl back down and let it sit for a bit thinking it was likely flooded. Tried it again later and still no signs of firing. The float level was now in the window and the primaries were no longer dripping. I let it sit over night and tried it again this am and unfortunately the same result. 

I tried opening the throttle (while still in neutral) to give it additional air and no luck. I tried a little starting fluid and no luck. No signs of firing. When I did leave the throttle open or tried the starting fluid I did get some pops (like coughs) but not like starting. Acted very similar when launched last and it finally started (GF look number 1 for reference). Although this time, it doesn't even act like it wants to start. I am at a loss and a little frustrated at this point. I don't want to kill this starter and create more problems than I already have. Just to back up, the last time it was firing was at the lake right before it died. 

Am I missing something? Any thoughts?

JQ was able to walk me through visually confirming that there is fuel delivery which there is through the accelerator pump when the throttle is depressed. Also that I have spark to each cylinder through using an in-line spark test light. All checked out. In checking the timing, there appears to be some inconsistencies that I need to confirm. The timing now seems way off (which is really strange) but I need to confirm and I will be working on that and will report back as soon as I can get some of the timing numbers confirmed. Thank you JQ! I guess the good news is the new fuel pump appears to be working even if the boat isn't starting. I'll take small victories where I can get them at this point. 

What did you do about all the leaking fuel in the primaries even when the float was adjusted?

Any leaking fuel in the secondaries?

There is no more leaking in primaries. When I adjusted the float back down and after a few more attempts at starting the float level is now back to the middle of the primary window and seems to be holding steady now with no additional leaking in the primaries.

After confirming fuel and spark, I moved back to checking the timing again while turning it over although it is not starting. It appears that the timing is now at 90*. There is a Mr. Gasket timing tape on the harmonic balancer, I think the harmonic balancer is what I'm looking at.  I did it a few times because I was so confused. I had set the initial timing myself at 12* as posted earlier and I had also confirmed the TDC marking with TDC at #1. So it was all good at one point. The distributor is securely in place with the nut that holds it in place also secure as well. The distributor doesn't have appeared to have moved.

Had some weather move through so had to take a break for now. Next I am going to go back and check TDC again at #1 and see what the timing mark says now and go from there.  Thoughts?

I was able to physically check that when the #1 cylinder is at TDC, the marker is also pointing at TDC on the harmonic balancer. Not sure why the light was showing different. It's not the most expensive light. 

I also physically inspected the new DUI distributor and the rotor was pointing to #1. The rotor and cap appear free from any cracks/defects and the advance mechanism moved freely.

I also checked the breaker at the rear of the engine and it has not been tripped. 

In discussing with the GF about when it died on the water. When I heard a pop, which sounded like it came from the carb (but I could be wrong about where it came from), she says she also heard a metal clank. When it died, it just died. No sputters etc. 

I am at a loss at this point. Any other thoughts?

For no start and a clank or pop when it died?   Not much to guess with.

When things don't work for me I go back to the basics.   

Verify compression in all 8 cylinders.  Does not matter if you did this one week ago, something changed and you are trying to find what changed.  If you have good compression on all 8 you know your valves are opening and sealing as intended so that tells you the timing chain and cam are spinning as intended and rules out many other potential issues.

On your timing, if static timing, engine not running is set to #1 at TDC and your distributor rotor is pointing at #1 on the cap Timing is close enough to start the engine, spin the engine over with the dist cap off just to verify the rotor is spinning as it should.

If it starts now I would make sure the Timing light is connected to the #1 cylinder and set the initial timing to 8-10*.  Next with the timing light still connected engine running watch your timing marks as you raise the RPM slowly and see at what RPM the timing stops advancing.  As you rev and slow the engine speed the timing should advance and retard smoothly and exactly the same every single time in sync with RPM.  Full advance is usually somewhere between 2,800 and 4,000 RPM.  Keep raising the RPM till the timing stops advancing and is stable.  So if you think it quit advancing at 3,500 take it up to 4,000 just to make sure you are correct.  If you have a dial back timing light this will also let you know exactly how much timing the engine is getting at what RPM.  Normally you will see between 32 and 36* fully advanced.   You stated timing was  90* off, sounds like you may have grabbed another wire by mistake.  An 8 cylinder engine fires every 90* of rotation so being 90* off might just be wrong wire as a source and that wire would be right next to your #1 wire location so either the wire left or right of #1 on your cap.

If it is getting spark and your Spark is at the right time, It is getting Air, (the choke is wide open)  and has compression it should start right up.

When you find out which part is missing/no longer there, you know what to do next.

With fuel delivery visually confirmed, spark at each cylinder and the distributor functions checked and confirmed as well, I will be moving on to checking the compression at each cylinder again. The good news is I have the compression numbers when the DUI was installed  by the mechanic and well before it died on the lake. So I at least have a baseline of where they were.

So onto the compression check. The compression numbers were in the (140-150ish range) before it died and the boat only has 408 hours. I do not want to even consider internal failure at this point as far as we have come. Although, I have gone from a great running boat on the trailer to a boat that doesn't even start now. Perhaps we should start looking at the mechanic now (me). Ha. I guess the compression test on each cylinder will let us know something, but I hope not.

It may take me a bit to get the compression check done, but I will get it done and report back. Any other ideas until I get that done are greatly appreciated as well. Thanks everyone. 

Just wondering out loud....how did you perform this test?

I should also mention that I had done this earlier before it died on the lake and when it was still running (except for verifying rotor position). With the previous issues, I thought maybe someone had installed the timing tape incorrectly but it checked out then as well. 

Fuel today over 6 mos old is suspect.  Over 1 year old is certainly degraded and older than that can cause bad problems.   I fixed a boat last year that had 4 year old gas in it.   It was fuel injected and 5 of 8 fuel injectors plugged up on the old fuel.    

Engines running on old gas will stink, it is an odd smell out the exhaust but you even smell it on the spark plugs when removed.  It can make your valves stick inside the heads.

Water in fuel is another concern.

If we have good compression, Good Spark on time and fuel they run.   Yours has us thinking out of school for odd solutions.

Maybe spill some fresh gas down the carb and turn the key.

On a side note:  What lake do you go to?  I am going to Saguaro tomorrow for a day trip and will be at Apache for Labor Day.  Maybe you need a old retired guy to help.

Thinking out of school for odd solutions as you stated may be exactly what is needed if the compression test shows no internal problems. 

Regarding the fuel, I did drain all the old fuel out of the tank when I first started this project as it had been sitting for awhile and it was definitely no good. No junk or rust but bad fuel. Since then I have maintained a fuel stabilizer and before the last launch I siphoned the majority of the fuel out so I could use new fuel with the new carb. My old lawn mower seems to run on anything so it gets the fuel hand-me-downs from the boat. 

Trying some more fuel down the carb and giving it another try is first on the list after checking the compression. Thanks!

Great suggestions! The issues of dying on the lake, then no fuel in the primary bowl, doesn't want to re-start and then finding the failing fuel pump after getting it back home. That is a lot of failures in a very short period of time to be completely unrelated. I agree with you that the way it died doesn't sound fuel related with no sputters etc. 

I do have the old carb and it did at least start the boat and ran on the trailer so that's a great idea as well. After the compression test is done (assuming it's good), then I will try some more fuel down the carb. If that doesn't work then swapping out the carb is the plan!

Typically have been going to Lake Pleasant for now since I know they have a tow boat until find some reliability.  I will gladly accept the help of an "old retired guy" as you say. That is extremely generous of you and I really appreciate the offer. I would not feel right taking time away from your boat days or your time on the water until I get my due diligence done first with the compression and possible carb swap as you wisely suggested. If both of those fail to provide some answers then I will absolutely take you up on that offer and head your way for assistance. I know my trailer works.  It may take me a bit to get these done with some other priorities pending but I will update as soon as I do. 

Also, regarding your trip to Apache, I recall someone mentioning that one of the ways into Apache had been washed out and I thought the only way in was from the Roosevelt side. I could be wrong and they may have made some repairs but I would check just to make sure for your trip. Enjoy the lakes and thanks again!

It's a DUI Ford distributor and you can see the plate that locks the 8 legged pickup coil in position so it can't move. The pickup coil moves if you have vacuum advance like in an automotive distributor and the plate is one part of the "conversion" to a marine distributor.

If anything is broken so that the pickup can move, it has about 45 degrees of movement which just happens to correlate to 90 degrees of timing at the crankshaft

Probably a long, long shot but it's free and easy to check 

That is definitely something I can check and see if there is any movement. These are new part names for me so thank you for the photos. I will give that a check and report back when I get it done. 

Your post got me thinking about checking the timing when trying to start it versus it running. When I checked the timing after it died while trying to start it, it was showing 90*. I then checked that TDC was correct as posted above and assumed we were good. My thoughts were that perhaps the timing light was off due to the balancer not spinning fast enough like when its running or just an inexpensive light. So my novice question is if I know my timing light is attached to number 1 plug wire with no cross talk with other wires and I check the timing trying to start it, will the timing light still be as accurate as if when it's running? Meaning should it actually show 12* instead of some other number like 90*? I hope my question makes sense. This was my first time checking timing while trying to start an engine so I have no experience what the numbers should show when it's actually NOT running. If it should show 12* when trying to start and we know that TDC is correct start then your suggestion makes a ton of sense whether its long shot or not.

One more question for you if I could. The new fuel pump I put in to replace the old Carter pump, can I assume (which I did) it came with the fuel filter in it like the old Carter pump? I didn't take the new pump part to check for the filter as I didn't want to disturb any of the seals. I thought I better confirm while I am thinking about it.

Thanks!

Hey All,

I apologize for the delay in getting the compression check done but the results are in...and I don't think it's going to be good.

All of the cylinders registered between 150 and 160 psi except cylinder number 7 which registered at 90 . When a compression check was done by the mechanic when the DUI was installed, before the latest stall on the lake, his notes indicated number 7 was at 145. I should also mention that his earlier numbers where recorded at between 140-150 for all cylinders. So there is a bit of difference between his compression tester and my new one so it doesn't appear that cylinder 7 was failing previously.

I was so hoping that I just failed to seat the compression tester correctly on number 7, but after three attempts, I had to accept the reality that 90 was the number. 

Is this considered catastrophic failure requiring a full rebuild? If so, I can't wait for the GF look on that news. Any ideas how bad this is or could be and why it would lose compression so fast in one cylinder? Does this lack of compression in one cylinder explain the stall and failure to now start? Sorry for all the questions but this appears to be going down a whole new road I wasn't expecting and I am just trying to figure out the best next step forward. Give me the news, I can take it.

Thanks everyone. 

I'd squirt some oil in that cylinder and check the compression again to give yourself an idea whether it's cylinder head related or piston rings.

About an ounce or a little more squirted in, do the test and if the numbers come up a lot, it points toward rings.

If they don't come up it would point toward the valves or camshaft lobe worn way down.

Remember that metallic noise you girlfriend heard last time it was running right and quit.............she might be onto something.

It should still start and run pretty good as a V7 1/2 though

Thank you for the advice! I followed your instructions on squirting some oil into the cylinder and the PSI only came up 10psi from 90 to 100. That doesn't seem like a lot, but I have no idea as I have never done this before.  Can I assume I am likely looking at a valve or camshaft lobe problem with only a 10 psi increase? Wishful hoping on my part. Please let me know what you think?

Either way I will let the GF know she was right in what she heard when it died. That may be the trick to avoid the look about more upcoming repairs. 

Thanks

So while I don't like that she heard a noise when it shut down, then again you didn't hear it so it couldn't have been too noticable?  I would think with 7 cylinders with good, balanced compression, 1 with low but not hole-in-the-piston numbers, 90 psi is still some compression, that the engine would run pretty strong.  I wouldn't expect this to be your no-start and dies on the water problems.  Plenty of people have run 7 cylinder V-8's for some period of time, and like Ken said yours is a 7 1/2 cylinder given the compression you have, I'd bet that cylinder is firing and making some power.

I wish I was more help on your overall issue!

I am titling this post "BAD JU JU" which is also likely the new name of this boat.

I hope this post does not require me to turn in my CCF man card (assuming I have even earned one here yet), but after I was unable to find a solution to it not re-starting, it was time to take it to a professional shop. This is what they found...

1. The distributor gear had come off the distributor and was sitting down below. The roll pin holding it on was nowhere to be found. They reconnected the gear with a new roll pin. Anyone even heard or seen this before?

2. The rotor was damaged (broken plastic) on one side of the rotor head and the rotor head was slightly bent. I did post earlier that the rotor and cap appeared to be fine which likely led us astray. When I pulled the cap I didn't pull it all the way off as the wires were still attached and the side I was looking at was the non-broken side of the rotor head. They replaced it with a new rotor. 

3. While checking TDC with the valve covers off, they noticed that at TDC the intake valve at #1 was about halfway open. Which suggests that possibly the timing chain has slipped. Vacuum was also only at 13 PSI indicating possible incorrect/late valve timing (no vacuum leaks found). The engine now starts and idles but is failing with acceleration on the trailer. Also, the #7 cylinder with the new lower compression after the stall appeared fine from the top side. 

So it was decision time on how far to go at the shop. I decided to bring it back home and reassess at this point. I am obviously disappointed that all of these problems keep arising on an engine with low hours, but at least some problems have been identified. The noise when it died could have been either the gear coming off or chain slipping, or both. I guess it's possible that the chain had already slipped or was installed wrong causing lack of power issues in the first place, then the gear came off making the noise when it died? 

My initial thoughts are to tackle removing everything up front and working my way to the timing chain to verify if in fact the timing marks are lined up (or not lined up) as they should be at TDC. How difficult will this job be and any tricks to making the job easier? Does the oil pan need to be loosened or removed to accomplish this task?

Again, I want to thank everyone for their input on this now lengthy post, I do appreciate it. Any thoughts or suggestions on the path forward would be appreciated.

The roll pin is probably laying in the bottom of the oil pan. Pins can break if there's too much load from the oil pump, weak pin or in your case maybe it was a lousy fit and fell out. 

I'm curious about when the distributor gear fell off.  You did a compression test that showed good compression on #1, yet how could that be if the intake valve is open at TDC?  Something doesn't add up.

I know you've already spent an amount of money on parts, and a ton of time on this.  You've done an excellent job of following a troubleshooting path but the solution hasn't been as obvious as I might have first thought.  The money you've spent isn't wasted, the new parts will serve you well.  It might be time to hand off the project to a shop you trust and simply ask them to return a good running 351 to you.  You'd definitely want a discussion on scope of work first, but based on what we've been hearing it would be timing set replacement, time the engine, do a compression and leak down test for a health evaluation, at that point ask you if you want it buttoned up in running order or if any other work is recommended.