engine bogging down no power

Ok guys its been a long time since I've been on the site but I'm having some issue's with my 1978 mustang.Some feed back would be nice if you don't mind.First some info you guys need to know about the boat.The engine is a stock 302cid.Theres only 338 hours on the engine.I have the Prestolite breakerless ingnition kit installed in the distributor to replace the points and condenser.I also have the electronic coil installed for this breakerless kit.The 4160 Holley carb that I have installed on the boat is only 4 years old.This boat has run flawlessly within this time period that I'm talking about.A week and a half ago on the last day of vacation the boat started to act funny out of the blue.I was riding down the lake doing about 20 to 25mph and all of a sudden without touching the throttle the boat started to to die and loose power and then all of a sudden it would it would lundge and regain power.At times for the rest of the day the boat would run fine.It kind of acted like I got a bad tank of gas or I thought I might have a ignition coil starting to go bad on the boat,so I went on ahead and got a replacement coil from SKIDIM.Thinking that I may have solved the problem I took it for a test this past Friday and the boat ran great for about 30 minutes.All of a sudden without touching the throttle it would die and loose power and regain it again.At this point I'm now working the throttle back and forth and not getting any response from the engine.So I would back it back down into idol postion and give it gas.Sometimes it would respond to the throttle and somtimes it wouldn't.There are times where I could give it full throttle and the boat would just bog down and I would only be showing 1800 rpm on the tach,then it would catch and bog right back back down and sounded like it was missing very badly.So my thinking is either the breakerless kit starting to go bad or my carb is not functioning like it should.
So this is what I've done.Once I get the boat on the trailer,I did the normal checking of the plugs,wires,inline fuel filter,the little screen filter in inlet of the carb to make sure nothing was loose or clogged.Nothing was found out of the ordinary.I even cleaned the vacuum screen on the carb.Once that was all done I started the boat back up on the trailer and it idols great.I even put a vacuum gauge on the engine to check the timing and I'm getting 18 to 20 inches of vacuum when the engine is up to temp and idoling.
Yesteraday I put the boat back in the water with tools in hand.Start the boat up,it idols great at the dock.I start to leave the dock and give it gas and its just a dog.It just can't get out of water.Its missing and then the engine will just shut off.You can put it right back into neutral start it right up again,it idols fine,give it gas and it will either die right then and there or it will run for a little bit,sound like hell and die again.
So my thought now is that it can't be the Prestolite breakerless kit going bad because the engines idols fine.My thinking is that its a carb issue now.I can pull the throttle button out and give the engine gas just sitting there and it will respond every time and rev normally.Put it into gear and it sputters,chokes and dies on me every time.The area where I live at they gas stations have ethanol in the gas and I'm thinking that could be my problem.I just would like to diagnose the problem properly instead of throwing and ton of money that doen't need to be spent.Any feedback would be great guys if you can help me.

Check the fuel pressure. Is there fuel in the clear line going to the carb?

you don't have to T in to the line just attach the gauge on the end of the feed to teh carb and crank it over severeal times and read the gauge. You need at least 5 lbs of pressure.

when at idle and in the drive there is no load no heavy demand for fuel. Also the line I was refering to is connected to the fuel pump samll 1/4 clear hose going from the pump to the throat of the carb. No a safty issue someone has created by adding a plastic inline fuel filter.

79, to answer your question no there is no fuel going through that 1/4" line that your refering dumping into the top of the carb.I am no carb expert in terms of rebuilding them can you please tell me what that power valve does in the carb.Tim your not the first person to suggest the power valve replacement.79 could the power valve also be the problem I'm having if I have the proper fuel pressure that your saying that I need as Tim is suggesting.

How old is the fuel?

I have a 71 stang with a 302 and am having the same exact problem you are. I bought a new fuel pump and 4160 re-new kit of course with the new carb and spacer gaskets. Im gonna tackle it tomm afternoon my boat does it more often when its underload as well. Sometimes it will run just fine when not in gear. Im pretty sure its the fuel pump but Im not gonna play around and do it all for piece of mind. Oh and the renew kit comes with new powervalves from skidim.

Just to get back with an update,I did check the fuel pressure on the pump and it was 7 lbs as you ask 79.As for Tim's suggestion about the power valve and I know 79 thought that it probably was'nt the problem.I did talk with Richard at SKIDIM today an ask there opinion.He also said fuel pump but that doesn't seem to be the problem.He also did say to check the power valves to see if they were blown.He said to turn the mixture screws all the way in to see if the engine dies.If it does then the power valves are good.I tried it tonight and found that the engine does did not die on me which leads me to believe this might be the problem.If anyone else has an comment or suggestion I would sure like to hear it.

Any chance of snapping a pic or two of the train wreck?

I'm curious as to why the metering block would be eaten up and even more so how to avoid it happening to me.

I'm not familure with the led addative. I've heard it was to lubricate the valve guides on older engines, but no one I know runs it on old stuff. Any chance it is addative related?

water sitting in the fuel bowl is what ate up the plate, not the subsitute or ethanol in the gas.

I subspect this boat has sat for some time resently in it's life.

metering blocks are available but not part of any kit I've seen.

That's awesome news.

Let us know how it runs after you install the new one.

Brian,
That's fantastic news on the carb. Sometimes things do work out for the better. However you'll be with out the boat for awhile. What did they tell you about the turn around time?

No opinions on the lead substitute? Maybe my comment about the Fram filter got to you? Don't tell me, you're a closet Fram filter user!!

Bri892001 wrote: Actually, when did boat motors stop needing led? I know you were talking to the other Brian, but figured I'd fill in.

First you need to know that lead was never meant to be a lubricant for internal parts of your typical engine. Lead was added as a octane booster to gas but it was found to also be beneficial to lubricating valve guides and cushioning valve seats. When the EPA banned the lead from the gas, the chemical companies marketing guys took over and created a lead "substitute" and sold it to the public!!! There is no such thing as a lead substitute and the stuff in the bottle doesn't do any good.

I'd like to take a step backwards in time - Marine fuel used to be "white gas". This is straight run gas from the refinery without any additives whatsoever. All the low compression engines ran fantastic on this low octane fuel plus it was the only gas you would find at the gas pier. These old engines ran without any hardened valve guides nor any hardened valve seats. Low octane but no additives!! White gas can still be found as a camp stove/lantern fuel. No additives to plug up the lamp mantels or the stoves orifices.

Run the engine and don't spend the $$ on "snake oil in a bottle". When the time comes for a top end job on the engine then you can decide what to do with the guides/seats. Some have chosen not to go with a rather expensive upgrade because their machine shop didn't feel it was worth the extra cost!!

All my boats as well as many friends I have though the ACBS have been running unleaded for years without issues!!

As mentioned, the other Brian got suckered into buying the stuff!! High mark up/profit for the retailer at the store or at the gas pump dock!!

EDIT: I forgot to comment about the Fram. Do a CCfan search on "Fram" and plenty of info comes up including links to in depth /cut open research on how bad they really are. The guy using the remote filter must have been paid to screw that Fram on there!!!   

I think the Fram people use the same marketing people as do the Jiffy Lubes....change your oil every 3000

71RR,

How hard would you say it is to do the carb renew kit?

My boat has a hesitation and I'm on the fence between doing a renew kit or getting a whole new carb.

I know I could remove and replace the carb without much trouble. So, I was thinking it would make sense to just replace it for a little extra verses paying someone to rebuild it.

Would you put rebuilding it at a beginner level, intermediate, expert? The more I read about 4160s, the more complicated it looks. Do you need and special tools or chemicals?