85 HP Force bogging down

kthkollar

Seaman Apprentice
Joined
Apr 30, 2009
Messages
34
I have an 85 hp force that runs fine in the driveway but under load bogs right down. It loses power in one cylinder. This happened out of town of course, took it to a marine mechanic who was known to work on these old motors. He said it was either a clogged exhaust port or a blown seal in the 3rd cylinder after checking everything else out, plugs, fuel, compression, etc. He said he has seen it before. I am not putting that kind of money into that motor so I am turning some wrenches myself and was wondering what anyone here might have to say about this. Anyone else had this problem? Thanks
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Re: 85 HP Force bogging down

Fill out the profile.What were the compression results.What year?Any info will help diagnose.
You check the fuel system?
Basics. Compression/spark/fuel.
Start with comp.Then go through the rest.Spark testers:A MUST have.
Ethanol is a big problem.
It could be as simple as a head gasket or a complete rebuild.More info!!! J
 

kthkollar

Seaman Apprentice
Joined
Apr 30, 2009
Messages
34
Re: 85 HP Force bogging down

compression check was done by mechanic, stated there were no problems. he also checked carb and spark. he is reputable and again stated there were no problems. thanks for your help
 

AmigoAzul

Seaman Apprentice
Joined
Sep 23, 2009
Messages
44
Re: 85 HP Force bogging down

I had the same problem a few weeks back. The boat ran great the first day I took it out and then the next day it ran fine till I was heading back to the dock to take it out. I was ruuning along fine and then it lost power. I replaced the fuel pump ( good thing I did as it was the original from 86 and all rusted) that did not fix the issue. I checked all the ignition wires on the starboard side of the motor from the trigger to the bus bar mounted on the right side. I had a wire just hanging on by a thread and once I touched it it broke off. The wire was for the number 1 cylinder. I stripped and crimped it and took it out again and it ran perfect. The next time the motor was out I had lost power on a cylinder again. Took the cover off and the number 2 cylinder spark plug wire had come out of the spark plug boot. I jammed it back in and taped it up good. It runs great again. I am replacing that coil pack as the PO had already done 2 of them. The moral of the story is check your wiring for any and all loose connections.

I hope this story helps out.
 
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