Hello ,
I have a Merc s/n OT463935 .
Bought used dealer said ran good and has good compression
90 psi all cylinders .
I test my self I got 110 on my Guage.
Problem is it ha always run like dog .
Chugs smokes, no power .
Performed cylinder drop test can pull top cylinder plug wire off runs same no change .
Pull middle cylinder wire off engine dies .
Pull bottom cylinder wire off no change.
Pull top and bottom wire off both engine stays running?
Seems like only runs on the center cylinder.
Replaced every electric part on this motor plugs, coils, regulator, trigger , stator , engine wire loom . Rebuild carbs with Mercury kits had rubber needles in the carb replace with factory steel needles. Still starts and runs horable . ordered new motor because I gave up last season. Now this year have to try again because the new motor still has no eta .
Any one have any ideas