Re: 74 evinrude
OK, a hard thump. You didn't mention that. That's different from a miss. It's very likely that you have a worn-out clutch dog in your gear case. Since this only happens at wide-open-throttle, and there's a hard thump, that's the most likely thing.<br /><br />An electrical miss that comes and goes could be a shorted wire or a bad connection, but it wouldn't make a thumping sound.<br /><br />A carburetion miss would not make a thumping sound, either.<br /><br />If this only happens when you're at full throttle or close to it, then my money's on the worn clutch dog. Replacing it will require disassembling the gearcase. When you do that, you'll want to change all the seals in the lower unit, so the lower unit will have to come off the engine.<br /><br />You'll need the manual for your outboard, for sure. If you're not comfortable doing this work, then have it done at a shop.
