Rpm's

[towboater1]

Have a 2003 90 hp Mercy 2 stroke and changed the water pump,went out this morning boat ran beautiful. On my way in RPM'S dropped to 2,500 and that's it. Got good water at Pee hole,oil injection seems to be working fine(no alarms). Not even a HI Temp. alarm. Could the Thermostat be in need of changeing as well as a overheat sencer.?

 

[Texasmark]

Re: Rpm's

You either dropped a CDI or a mysterious piece of crud got into one of your carbs to block the high speed jet. Your suggestions have nothing to do with your problem. I'd start with a dropped cylinder. A timing light sensor somewhat adjacent to a spark plug wire will tell you real quick who's working and who's loafing. Otherwise you have a clog in your fuel line somewhere, or possibly the fuel pump failed you. I have the '02 year of that engine.

Mark

 

[Silvertip]

Re: Rpm's

If it overheated you would have had an alarm. Does the alarm self-test work when you turn the key on? Feel the engine. Does it feel or smell hot? I think you just lost a cylinder. Make sure you have spark on all three.