Poor idle/acceleration on Force 85HP

dmann

Cadet
Joined
Jul 8, 2003
Messages
17
I have a 1989 Force 85 HP Outboard. Model 856L9B, Ser # 1624. I have had it for two years and it has run well at high rpm but tends to intermittently have an engine miss at idle. Most recently it tends to skip as the throttle is advanced and then it feels like a cylinder comes back on line and goes fine. The carbs have been removed and cleaned and the float levels set. It has new plugs. Spark tests at the plugs shows good spark when cold. It also seems to be worse after the engine warms up. The most recent attempt to set idle speeds resulted in the top cylinder not responding when the throttle was advanced even though the idle was set approximately to the factory recommended setting. After a brief hesitation the cylinder will come on line. Would appreciate any thoughts/suggestions on the problem.
 

dmann

Cadet
Joined
Jul 8, 2003
Messages
17
Re: Poor idle/acceleration on Force 85HP

If anyone is interested, I discovered that the top (#1) carb had restrictions in the idle ports. There are 4 small idle ports on the top housing. One of the ports is larger and is behind (between throttle plate and engine) and the other 3 are uncovered when the throttle plate is opened with advancing the throttle. These opening are smaller and 2 of the three were restricted. I have run it in a test tank but not had it on the water yet. I am hoping I have found the problem. Boating seasons in the northeast are short enough without working on the boat on nice boating days.
 
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