Rough Idle

[Iceman_ch]

I am having problems with my boat idling. My motor is a 305 (5.0) 1989. it has a alpha one outdrive. I have changed the water separator, distributor cap, rotor, and plugs. It starts when the gas is pumped and when it starts it wont idle. Does anyone have any suggestions?

Thanks

 

[Don S]

Re: Rough Idle

I'd do a vacuum test and a compression test.

 

[Iceman_ch]

Re: Rough Idle

By the way I forgot to mention one thing. My boat was in Utah (Way above Sea Level). Ran great everything was fine. I moved to South Carolina(Almost Sea Level) . Boat ran great for a little while then I started having the idle problems. I don't know if that will help or not but I will definetly try the things you suggested.

Thanks

 

[87 bayliner]

Re: Rough Idle

does it smooth out above idle speed? check for vacuum leaks. spray carb cleaner around base of carb and note if idle changes. ignition points may be wearing out. check the point gap. follow Don S.' advice. a vacuum guage and compression test can offer valuable clues.

j

 

[Iceman_ch]

Re: Rough Idle

I will check them out today.

Thanks

 

[Don S]

Re: Rough Idle

When it won't idle, do you get a lot of black smoke before it dies?
How high, in numbers, is "Way above Sea Level"

 

[Iceman_ch]

Re: Rough Idle

Way above sea level is somewehere in the neighborhood of 6100 feet. South carloina sits at about 300 feet so it a pretty big differnce. I've been told that there is enough pressure differnce to equal a small super charger. The differnce was big enough that I incresed the size of my prop by 2 sizes.

 

[Don S]

Re: Rough Idle

Yea, 6K will do it, had it been 2 or 3K it would have been a different story. Did you readjust the idle mixture on the carb after getting down to sea level. Usually they are too lean at sea level when adjusted for hi altitude