my 40 h.p. johnson, i think it is a '73, will run full throttle when in nuetral, but when in gear under load appears to only throttle up about 1/4 power.even with the throttle wide open i can only putt putt around. help me please.........
gordyB <br /><br />Sounds like you are not getting spark to one cylinder. Even one cylinder that's firing will allow the motor to rev up in neutral without the others firing. Check for spark on all cylinders first. Make sure it is a strong blue spark. Don't rev the engine in neutral to avoid damaging the motor. Just above idle is OK. Let us know what you find.
i had a merc like this, spark on all clyinders but no power, it turned out to be a bad coil, once it got hot it wouldn't work, eventally it cracked and i bought a new one