1998 125 help

[whaler 1]

Have a 125 merc salt water - engine runs rough. Idles fine, accellerates fine to 5200 which is the max RPM. When I settle into a RPM between 2500 and 5000 the engine runs rough and serges back and forth about 200 RPMs. Engine attempts to run smooth but cycles intermittently to running rough. It sounds as if the timing is not right. Dealer is stumpted. Compression is fine, carbs have been overhauled, box has been replaced, trigger rerplaced, lower seal is OK. This motor runs on 2 cylenders below 1800 and the other two kick in above 1800.

 

[WillyBWright]

Re: 1998 125 help

Welcome to iboats.<br /><br />I don't know if that has in idle stabilizer, but those can do strange things to timing sometimes. If it does, unplug it and run without and see if it improves. Check the vacuum on the fuel line as the motor runs. If it goes over 5 in hg, there's a restriction. If you can fit a piece of clear hose inline somewhere, you can see if you're sucking air. Otherwise I'm stumped too.