Boat is allergic to water !!!!

1984 Force 85 HP

Hooked up to the garden hose, starts great, idles great, shifts into gear nice and snooth --- sounds awesome.....
In the water, starts after the 3rd or 4th crank, idels OK (sputters once in a while), put it in gear --- bogs and dies or sometimes just stalls right away. Can never get to WOT, even at low idle speed in gear it vibrates a little and then dies.....

Replaced gas tank, fuel line, fuel filter, spark plugs. --- no different.

Im thinking its the idle adjustments on the carberator and also the Throttle stop screw on the side. So my question is, How is this done? Should this be done in the water or out? In gear or in neutral?

Im new to boating and kind of mechanically inclined so go easy on me.

Thanks

Re: Boat is allergic to water !!!!

First do a compression /spark test.
Then rebuild the fuel pump and the carb.
NO idle adjustments on the carbs thats an air/fuel mix screw.
Turn it in till it just bottoms out(gently)then out 1 full turn.
Then leave it there.That's the way the factory does it.
The throttle stop screw is for raising/lowering the idle.
Idle RPM's in the drive about 1100 in the water,in gear 750-800

Do these things and post the results.

Re: Boat is allergic to water !!!!

jerryjerry05 said:

First do a compression /spark test.
Then rebuild the fuel pump and the carb.
NO idle adjustments on the carbs thats an air/fuel mix screw.
Turn it in till it just bottoms out(gently)then out 1 full turn.
Then leave it there.That's the way the factory does it.
The throttle stop screw is for raising/lowering the idle.
Idle RPM's in the drive about 1100 in the water,in gear 750-800

Do these things and post the results.

Click to expand...

Sorry -- I did have a compression test done in all 3 cylinders -- 110-112-110. My buddy said that was a good range.

Re: Boat is allergic to water !!!!

The behavior of a bad outboard with no load on it and no back pressure on the exhaust fools a lot of people, Delta. It does NOT run great on the muffs, it just pretends.

You could be down a cylinder or more, your L&S could be off the chart somewhere.

Do what JJ suggests, and do a link 'n' synch by the book.

Good luck.

Re: Boat is allergic to water !!!!

Roger That. Ill give it a try this weekend on the water and let you know what happens.

Thanks

Re: Boat is allergic to water !!!!

A good running engine on muffs but rough and dies in the water is usually caused by low idle setting, improperly set air screw or most likely leaking exhaust either from the idle relief exhaust hose or from the exhaust gasket. Idle setting in neutral is between 1000~1100 RPM. Idle setting in gear is 700~800 RPM. The air screw setting is as mentioned by Jerry, 1 full turn backed out from lightly seated. You can try going 1 1/8 or even 1 1/4 out if it improves idling or shot out of hole.

Now for exhaust leak, the bet way to diagnose is while in the water remove the cowling and check for exhaust coming out from the lower part of the engine. Or better yet see if removing the cowling improves idling. If it does, there is a very good chance you have exhaust leak somewhere.