1995 Force 120 stammers at 1500-1900 rpm

kody29u

Recruit
Joined
Jun 30, 2011
Messages
3
This motor has about 150 hours and runs good at idle and WOT. But when running at slower rpms (1500 to 1900) the engine feels like it's got a fuel problem, maybe too lean. I tried Sea Foam but no dice, and tried adjusting the mixture (which is now at 1 1/8 turns out) to no avail. Running clean gas with QuickSilver and new NGK plugs - BUHW. The boat was originally rigged in Ft. Collins, CO. (elev about 5000 ft) and that's about the altitude I'm running at. Don't know about the carbs if set for altitude or not. Is this a characteristic of the engine or where's the best place to start trouble shooting?
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: 1995 Force 120 stammers at 1500-1900 rpm

My 1988 125HP does the same thing at about 1200 - 1500 RPM's. Not real bad but you can definitely tell there's slightly more vibration and it doesn't sound happy. Below and above that RPM range it runs great. I think it's the nature of the beast.
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
Re: 1995 Force 120 stammers at 1500-1900 rpm

My '86 also. "Nature of the beast" to qoute a well known replyer
 

kody29u

Recruit
Joined
Jun 30, 2011
Messages
3
Re: 1995 Force 120 stammers at 1500-1900 rpm

Some answers to my own question. Discovered a hairline crack in the engine mounted fuel connector. Replaced and/or added clamps to hoses on the engine. Maybe too much air being sucked in. Runs a lot better now. Only a light flutter at those low to mid rpms.
 
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