S.O.S. - Part Deux

Jllogan wrote: 76tique wrote: Yes, I do have the one-way rubber flaps installed. Curious why you asked - I have read in other threads on this site that the flaps are unnecessary. Does anyone know the purpose of these flaps?

Justin, the purpose of these flaps is to prevent water from being forced up the tailpipes when the boat is in reverse.

Tom - I recommend cleaning up the mounting surfaces by getting a flat wood block (short 2x6 for example) & stapling some emery cloth to it. Then keep it flat on the surface & sand until cleanup. No gasket sealer is needed. Run a tap into the threaded holes for cleanup of threads. Use new stainless screws. Torque to about 20 ft lbs. Use anti-seize on the threads.    Great that you found the problem.

Thought I would update this post...I've run another 40 gallons of gas through the boat and no signs of any water in the oil. Risers are still running hot with some steam out the exhaust on acceleration. I finally pulled them off to check out the gaskets tonight (way easier than I thought) and just as I suspected the gaskets were installed backward, with the blocked off part forward. Hopefully hot riser problem solved.

From what I can see, there isn't much corrosion going on. Didn't see any obvious water path through the gaskets. I was going to have the manifolds pressure tested, but now I am not so sure I want to remove them. Worried about breaking off bolts in the heads. I am thinking of just cleaning up the riser mounting surface and reinstalling with new gaskets. What do you guys think?

Some questions on reinstalling...

1. Should I use some kind of gasket cement? P/O seems to have used something.
2. How much torque on the bolts? I can't find a spec in the service manual.
3. There is some corrosion on the bolts. Good idea to swap to stainless? Or stick with these and use never seize? Never seize a good/bad idea for any reason?
4. What is the best way to clean mounting surface? I have scraped off with a razor blade. Was thinking of using emory cloth and a flat block to try and smooth out a bit, particularly the aft part of the water jackets where there seems to be a little corrosion.


Pics: note the risers are wet b/c I flushed with a garden hose to remove some rust scale above where the blocked off gasket was. Deposits inside the port manifold dropped out of the front of the riser when I pulled it off. I didn't see any obvious cracks/leakage looking down in the manifolds.

Port Manifold:


Port Riser:



Starboard Manifold:



Starboard Riser:



Any and all opinions appreciated...I am looking to get the risers reinstalled within the next couple of days. As always, thanks for your input guys!!

76tique wrote: Yes, I do have the one-way rubber flaps installed. Curious why you asked - I have read in other threads on this site that the flaps are unnecessary.

Does anyone know the purpose of these flaps?

Cool,

Thanks for the response.

Donald

76,

Did you have to do much tuning on that new carb or was it mostly plug and play?   I am glad you do not have bigger problems at this point.

Donald

I guess it makes sense that the manifolds would be hotter now. Cylinders that aren't firing aren't generating any heat.

How is the temp gauge reading? Also, not sure if you mentioned if you checked the impeller etc. Are you pretty sure you're drawing in enough cool water (ie bucket test)? Worth checking before you pull the manifolds.

That's awesome that you got it running well

Yes, I do have the one-way rubber flaps installed. Curious why you asked - I have read in other threads on this site that the flaps are unnecessary.

Thanks Brian. Definitely a confusing diagnosis with the battery cable issue I was having that day. Don't know why I didn't put that together sooner. I am thinking that a hydrolock might more common when sitting or cranking for an extended period due to the lack of exhaust gases flowing out the manifold /riser, if it is a minor leak. But really have no idea. The article you sent really makes me want to pull the exhaust manifolds or at least risers and have a look!

Guys, thanks so much for your continued comments on my issues. Luch, I agree that unnecessary spending on parts would be foolish by me at this point. However, I have given some more thought to things. Brian, thanks for continuing to spur on the thought process here.

Not sure how much water it would take to be noticable in the oil. However, the last time I drained it (after 6 hrs on the lake) I didn't see any evidence of milkiness. I'm not actually 100% positive that the oil level was elevated after my last time out, as it looked ok with the boat in the water but measured higher on the trailer. I'm thinking that it might not be quite level on the trailer. Lately I have been thinking there may not have been any water as it seems to me it wouldn't take much to be noticeable.

Also, I have given more thought to what happened the day before I found the milky oil. Right at the end of the day, the boat was idleing very rough and stalled when my buddy was about to put it in gear to give me a pull. He was unable to start the boat and was having trouble getting it to crank with me in the water. We had been having trouble starting the boat all day due to a bad negative battery cable connection (which I have since fixed.)

I got back on board the boat, fiddled around with the negative connection, and got the boat to crank, but just barely and after a lot of fiddling. After several tries, it finally cranked fast enough to start and we headed back towards the ramp. We ran into our buddies (Mark Mel and Joe) just about at the ramp and shut down to chat for a while. This time on startup the boat cranked right over. We headed back to the ramp and pulled the boat as it was sunset. I found water in the oil a week later when checking it before heading to the lake.

At the time, I thought starting issues were all due to the bad battery connection. However, now I am thinking the boat may have been hydrolocked and that is why it cranked so slowly. So I am still thinking bad riser gaskets/manifolds on the water issue.

Is there any way I would be more likely to get more water in the cyls after excessive cranking with no start, if the riser gaskets/manifolds were leaky? As I am now thinking my buddy was cranking it a bunch with no start and me in the water before it started turning over slowly that day.

Amazing how complicated these issues can be, I am hoping with the new carb and better idling I won't be stalling/cranking so much.

I guess the two questions are - how much water in the oil to make it look milky/noticable? And, is my hydrolock scenario plausible? Right now I am just planning on running the boat after new carb/tuneup is complete and see if the hydrolock condition occurs again/keep a very close eye on the oil. Does this make sense? Should I be pulling manifolds to check first?

If you guys are still reading at this point, again, thank you all so much for any input!

Dont want to be hard on you but I'd wait a little for ordering unneeeded parts as you might be saving for some more expensive later.

Concentrate at one issue at the time, the oil/water issue is the most important I think. Then you play-tune it, carb and ignition.

How does the oil look now?

Tom,

Just to throw a curve ball at you. Is there a possibility your carb is leaking excessively, to the point where gas is getting into your crankcase? With that really fouled plug, and hard warm startup, I'd say you definitely have a fuel leak issue. A leaky carb can load up the engine, and make it tough to start. If it leaks enough, it can get past the rings into your crankcase too. Was that really fouled plug towards the back?

Next time you have your motor running, carefully remove the spark arrestor. Then shut the motor off. Tilt the choke plate if you have to and look down all 4 barrels. If you see fuel continuing to drip, then you have some kind of carb issue.

I'd tend to want to look at your carb before pulling the intake manifold, as it sounds like you could have issues there anyway, especially if you are no longer seeing obvious signs of water.

im with Luch, at some point you would notice a hydrolock if the exhaust manifolds were leaking, Yes they do look like they are leaking and need to be addressed, but, how is the oil now after a few runs?
im still leaning towards the intake as being the culprit

Hmmm, hot compression checked out...6 cyls at 125psi, two at 120psi. I guess that eliminates a head gasket/head issue?

Other stuff - Trying to figure out the fouled plug on #6 - Installed a new set of Autolite 24's gapped to .035, tried pulling some plug wires at idle, she definitely idles rough when warm, strangely #5 and #1 didn't seem to make much difference when pulled but the other plugs dropped rpm considerably. The cap and rotor look a little tired, I think I am going to change rotor cap and wires just for the heck of it. Discovered that the timing was way advanced - like 20degrees BTDC at idle. Weird, but she backfires on acceleration (no load in driveway) when I set it at 6 degrees. Hoping the cap/wires are the problem with #6.

Also noticed fuel leaking from the plug over the secondary float adjustment. Can this be fixed by rebuilding carb? I'm debating springing for a new Holley to see if it fixes the idle issues + take care of that fuel leak - makes me nervous.

Anyway I'm getting off topic - I think my next step on the water in crankcase issue is to pull the exhaust manifolds, have them checked out and reinstall with new gaskets. If that doesn't fix the issue, I guess the next step is to pull the intake manifold and check that gasket out. Do you guys agree? Or am I being premature thinking that the heads and head gaskets are ok based on compression test?