Merc 225 won't run above 1000rpm when first started

rprichoux

Recruit
Joined
Jan 12, 2006
Messages
2
I have a 1996 Merc. 225 carbureted model that is not running properly. I'll start with a brief history. The compression is within specs on all cylinders, new spark plugs, new water pump (impeller, housing etc), new fuel pump kit, new TPS adjusted to specs., new coolant temperature sensor, new fuel filter, new fuel/water filter, new fuel and oil injector lines, cleaned carbs, syncronized carbs, adjusted oil injector pump.
THE PROBLEM..The engine will not run above 1000 RPM under load when first started. If I advance the throttle above 1000 rpm, the engine dies. It will start right up but still will not go over 1000 RPM (in neutral, it revs up fine). After about 10 minutes of driving around at 1000 RPM, I can push on the throttle and it responds perfectly up to about 5200 RPM. I can slow down to idle, stop and restart, pick up to speed with no problem BUT, if I shut it down for longer than 15 minutes or so, I have to go through the ritual of driving at 1000 RPM for 10 minutes for it to start running normal again.
Any help would be greatly appreciated.
Thanks,
Ralph
 

Pitusa

Cadet
Joined
Aug 14, 2006
Messages
7
Re: Merc 225 won't run above 1000rpm when first started

Dear,

You need to clean your carbs...one by one. ALso, confirm the N°of the main jet. Confirm the best number for a rich mixture...maybe you are running your engine to lean...this is dangerous for your engine.

Regards

Carlos
Venezuela
 
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