I have a Mercury 7.5, not sure of the model, maybe somewhere between 79-81. I think the ser no. is 5527139.<br /><br />Anyway, it cranks easy. Goes into forward and reverse easy. Pulls away from the dock fine, but when I give it throttle, the motor winds out but doesn't push the boat along any faster.<br /><br />I don't know a thing about engines, but it is almost like it starts off in low gear but won't shift into high.<br /><br />I've got the motor on a 12 foot john boat, and I swear it'll only push the boat along a fraction faster than the trolling motor does.<br /><br />Any ideas what may be wrong?<br /><br />I've got a copy of Chilton Marine's "Mercury Outboards 1965-91 Repair Manual", but I don't even know where to get started in trouble-shooting the problem.
