25 hp merc woes

[bigbadplad]

the motor starts on the first pull but runs like its missing, it does the same thing as the throttle is reved up. any thoughts?

 

[Mi duckdown]

Re: 25 hp merc woes

More info. Serial number, year?

 

[bigbadplad]

Re: 25 hp merc woes

its a 1992 25 hp merc s/n odo89207, I have replaced the stator( high speed coil shot) rebuilt the carb replaced #2 ignition coil, checked trigger output, same voltage on each lead, checked spark plug wire resistance,set timing, throttle cam opening,adjusted mixuter, checked quality of fuel, checked flywheel magnets, both stop switches check out fine. Checked the recirc lines, all the crankcase side plate cover orings. I have done the old propane leak test, Im about out of ideas, the only thing I can suspect is the lower crank seal is leaking although I dont really have much for oil/fuel leakage when running

 

[gears]

Re: 25 hp merc woes

did you try replacing the spark plugs and setting the gap?

 

[bigbadplad]

Re: 25 hp merc woes

yes the spark plugs have been gapped to .040'' as per the merc owners manuel. Ive even tried setting the gap a little closer just try and see if it makes a difference. yesterday I rechecked the float setting on the carb(1" is the spec) Im bang on with that, the spark plugs are always wet with oil and fuel and when the throttle is raised the engine almost acts like its starving for fuel, its like a hunting governor in a diesel engine. Im getting to the end of my patience with her, about ready to bring out the BFH