85 force won't run hard under a load

[dav0]

my 89 85 hp force just stoped runing great when it was in the water, it starts right up and run fine to half throtle then cuts out and starts missing, but when you throtle it from there by hand it runs like a top .
could this be one of the coil packs? help

 

[john from md]

Re: 85 force won't run hard under a load

I'm confused. What does trottle up by hand mean? How else would you apply power?


Your problem appears more fuel related than spark. When was the last time you cleaned your carbs or replaced your fuel pump? Does this happen all the time or just intemittantly?

John

 

[dav0]

Re: 85 force won't run hard under a load

what i ment was by hand was cover off motor someone else driving and im at the motor useing the linkingege by hand opening the carbs. i cleaned the carbs last summer and have never replaced the fuel pump , is this hard to get too and what dose it look like & were is it located, and i'll check it out in the morning , ive got plenty of time just had an a c l reconstruction.

thanks and it happens all the time.

 

[john from md]

Re: 85 force won't run hard under a load

The fuel pump is on the right side of the engine (facing forward) where the fuel line goes in. The cover containing three check valves is held on with six common head screws. The pump is just a diaphram that is operated by engine crankcase and exhaust pressure.

I suggest that you get a Clymer manual for the engine and also replace the three check valves. They are only $5 each.

John

 

[dav0]

Re: 85 force won't run hard under a load

thanks i'll pick-em up & get a manuel and give it a try . do they come with a rebuild kit for the pump or is this seperate , i'll check it out and let you know.

dave

 

[john from md]

Re: 85 force won't run hard under a load

The check valves are purchased separately from the pump diaphram kit. I think I bought mine from a place called marine engine parts or marine parts, something like that. They are on the web, just do a search for force outboard parts. The price for the pump diaphram kit was about $16 and the check valves were $5 or so each.

You will need to pull one check valve out with a tube type easy out or make some kind of puller for it as it is pressed into a blind hole. The other two are easy to do as one has two screws and one has an open hole to use a drift pin to tap it out. I used sockets to press them in on my small arbor press but you can tap them in as well.

Don't forget to buy one gasket for the center check valve. The other two don't get gaskets as they are pressed in. The center one is held in with two screws and has a gasket on it. Gasket is about .50.

Hope this helps,

John

 

[dav0]

Re: 85 force won't run hard under a load

ok picked up manuel and all parts, & gaskets , did the reinstall ,she started up and now im working on adjustment's on the carbs, as they got a rebuild also. it seems to run lots better, not sure if im adjusting the carbs correct, don't have a tac , is there a sure fire way way to adj them without a tac or a shops help, im pretty good by ear what do you think.


dav0

 

[john from md]

Re: 85 force won't run hard under a load

Dave,

Buy one of the inductive tacs off of ebay or sears. They go from $10 to $20 on ebay and are around $29 in sears. Then you just follow the manual as far as turning the screw out, then in then set it in the middle of the two extremes.

Regards,

John