Problems.....

[bugging57]

Hello, I have a 1990 Bayliner with a 5.0L LX motor. I bought it 2 months ago. The motor ran great at first but then started to stall and sputter after a few hours. The engine became difficult to start after that. Once it started, if I kept the RPMs below 2400 the engine would run fine. I though possibly the fuel filter might be the problem or maybe the coil. The previous owner had it stored for 3 years with some fuel left in it. I replaced the fuel filter and the coil. I took the boat out and ran it all day with no problems. It started up immediately with no hesitation. After about 8 hours of fishing we ruturned back to port and the engine started acting the same again. The coil that the shop sold me said that it needed an external resistor or a resistor primary wire. My old one didn't say that on it. Is it possible that the coil could be the wrong one or do you think it is a fuel flow problem?

 

[ktbarrentine]

Re: Problems.....

I have a 1990 5.0L as well... Although our problems sound similar, the exact cause is probably different, so I'll let the more experienced ones on here provide your troubleshooting plan. In my case, It came down to a bad fuel pump diaphram that provided excess fuel to the carb airhorn during operation, which made it hard to start when warm (after awhile the fuel in the pump will degrade the diaphram....especially if left there for 3 years). Easy to spot this problem, by looking at the clear site-tube that goes from the fuel pump to the top of the carb. Should be dry. Like I said, our problems sound similar, but many things can cause these. A 22 year old fuel pump was my smoking gun. Good luck!

 

[bugging57]

Re: Problems.....

bump

 

[makonnen]

Re: Problems.....

well I'll give this a shot since no one else has so far...

IMHO its not likely a coil problem. Ignition coils don't behave that way. A coil will miss under load, sometimes they will leak spark through the case or at the terminals, sometime you can hear it leaking, sometimes you can see it leaking in the shade ... but coils will rarely work perfectly for a few hours then start to run that bad.

I would say you're chasing a fuel problem. Its also not likely for a carburetor and fuel pump to work perfectly for that long then crap out.

Here are some things to consider

- bad gas
- pickup tube in gas tank clogged / corroded / damaged
- gas tank vent blocked thereby creating a vaccuum in gas tank as gas is being used
- fuel line to carb restricted
- choke operation problem???