305 Chev - Boat I/O - I could use some help.

[Marcarl]

Apologies for jumping in here w/ my own issues, but this thread came up in my Google search and I'm desperately looking for some guidance before I start throwing more money than the boat is worth to a marine mechanic!!! Any help would be appreciated, I noticed Saddlebum had some great input in this thread, but I couldn't figure out how to message him directly.

 

I have an old 88 Bayliner 2150 Capri Cuddy w/ a GM 5L 305 V8 w/ points & condensor etc. The boat runs flawlessly from a cold start, and runs, stops and starts fine on a leisurely 7 knot cocktail cruise. But if the engine is worked harder, like taking the kids tubing, or cruising for a while at 3000 rpm, it suddenly will have difficulty starting and maintaining idle, and when it does turn over, the idle is weak, causing it to immediately die when put into forward or reverse gear. Very frustrating, has left me stranded on the water for an hour or more until I presume it cools a bit and I am able to just barely get it in gear without it dying so I can get back to the dock. In the morning, it starts up and idles just fine.

 

Thanks again for any input!!!!! Chris

Take the points out and replace them and the condenser,,, or at least file them with a points file,, a points file, did I say points file? then adjust the gap to proper spec's, probably somewhere around the 35 thou. range,,,, might be the issue.

[wes0778]

Hmmmm BOAT= (B)reak (O)ut (A)nother (T)housand... :rotf::rotf:

 

 

I'll go back to my corner now...

[winston66]

It sounds to me that the motor is having fuel starvation problems when being run for a while at part or near open, full throtle.

I would check for restricted fuel flow at the input to the carb, is there a very fine mesh screen interegal in the last banjo fitting to the carb?

I would also check the output of the fuel pump , both the pressure and the flow rate.

If these do not solve the problems then I would make sure that the breather to the fuel tank is not blocked, ie that the fuel cap has a small air hole in it because if the tank cannot breathe, when a reasonable amount of fuel is being sucked out of the tank eventuallv enough vacumme will be caused and the fuel pump wil be unable to provide any go juice to the motor, it is likley then that after a while the tank will breathe a bit ie the next morning or after an hour or so and then the fuel supply problem will be eased and the motor will function normally again , untill the partial vacumme stops the fuel supply again.

Hope that this helps.

Regards Winston66

 

:detective:

[Gary N.]

Take the points out and replace them and the condenser,,, or at least file them with a points file,, a points file, did I say points file? then adjust the gap to proper spec's, probably somewhere around the 35 thou. range,,,, might be the issue.

 

For under $100.00 convert it to electonic ignition with this http://www.pertronix.com/prod/ig/ignitor/default.aspx and never worry about points again. I've done this to a couple of old Chevy small blocks and they work great.

[ctraylor]

Just my 2 cents, did you think to check the vent in the fuel tank. If the tank is not vented it will run good for awhile and then quit.

[yamtom]

I cant believe the ability of you guys to know how to fix these things, even stuff thats off list. After reading all your posts, if that thing isnt found by doing all those things, then do the gas cap rebuild is what I say.

[RedRider]

Nothing to add relative to fixing your problem. However, since it has been out of the water for a couple of years, replace the impeller in the final drive. This pumps the water through the cooling jacket. They dry out and fall apart. Don't ask me how I know.

 

Sold my boat 2 summers ago and don't miss it at all. It also put $2000 into my 'toy' fund.

 

RR

[waterbug]

I had a tinker with a 454 and she would do that and it was the main wiring harness would get warm and vibrate lose enough to cause elec fits! Clean the plug good and put some elec grease in it then use wire ties and tie it together. If not that look at the vent tubes in the fuel system