1988 force 85 dies when coverd

silvace

Recruit
Joined
Jul 28, 2010
Messages
3
I just picked up a 17 foot larson with an 1988 85 hp force outboard for 700 bucks. I am trying to work out some engine issues. When starting I must shoot a little starter fluid into the carbs then it starts right up and idles just fine with the cover off. Once i put the cover on the engine dies within a minute or so. When I engage the prop it runs fine as well with the cover off. Once I put the cover on it becomes gutless.. Any suggestions? It almost seems as tho its getting choked out by exaust. The engine runs a little smokey so I leaned out the fuel and it helped a little but the problem still exists. Also when full throttle every once in a while the engine will cut out a little. I have replaced the plugs and fuel filter with little results.
 

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
Re: 1988 force 85 dies when coverd

You may have an exhaust leak at the rubber boot connecting to the two ports on the rear of the motor where you normally see water and exhaust exit. Inspect the rubber boot for tears, damage. If its bad enough it will affect the way the motor runs.

I would recommend not using starter fluid (it has no lubricating qualities) These motors are notoriously smokey. Don't lean out the fuel or you'll be rebuilding - 50:1.
 

ezimmerm

Petty Officer 3rd Class
Joined
May 31, 2009
Messages
94
Re: 1988 force 85 dies when coverd

+1 for furthers advice.

Check that boot, especially at idle or slow speeds even a small leak with cause accumulation of gas under the cowl. At speed the air movement will get enough clean air in there to keep the engine running.
 

jason32038

Chief Petty Officer
Joined
May 25, 2009
Messages
555
Re: 1988 force 85 dies when coverd

Check the air inlets on the cowl also. Make sure nobody covered them with foam.
 

silvace

Recruit
Joined
Jul 28, 2010
Messages
3
Re: 1988 force 85 dies when coverd

i Replaced the boot which was actually in stock at our local merc shop!! 20 dollar fix. Thanks for the help. Now im thinking about replacing the waterpump and possibly the fuel pump. The engine runs much better but seems to surge a little. Im hoping changing these two pumps will help out. Does anyone have any imput on that idea? Or any good refrences to help with instructions.
Thanks
 
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