40 hp Force Motor - low rpm

[jo2man]

I have a 40 hp Force motor that was running just fine when put into water after winter storage. My peak rpm output was approx. 5200rpms. Suddenly the max with trottle wide open is only 3000rpms. Leakage seems to be fine. I replaced plugs and gas filter with no change. Help!

 

[Estaver]

Re: 40 hp Force Motor - low rpm

You didn't mention how it sounds. You may have lost fire at one of your plugs. Bad plug wire?

 

[jo2man]

Re: 40 hp Force Motor - low rpm

Thanks. It doesn't make any unusual sounds. It seems to be running fine but I can't get more than 3000rpms.

 

[stevecarr]

Re: 40 hp Force Motor - low rpm

my little 20 hp was doing the same on the rpm's<br /><br /><br />1 day fine , next morning only half the usual power...... just a fouled plug <br />hope your fix is as easy<br /><br />SC

 

[jo2man]

Re: 40 hp Force Motor - low rpm

Thanks...headed up north for the 4th and anxious to try ideas. Hope our fix is easy too hate to be boatless over the weekend.

 

[eurolarva]

Re: 40 hp Force Motor - low rpm

Pull your spark plugs and see what they look like. Both should be kind of black and a bit gritty. If one is clean you have a problem. Sounds like you may have lost a cylinder. You really should do a compression test. That will help find where the problem is