I got this motor from my brother in law and after cleaning the carb and plugs and adjusting the choke and putting some fresh gas in it starts and runs like a top. However, when under throttle moving through the water the motor is jumping almost as if there was a missing tooth or spline somewhere in the drive. It was even starting to act as if it was slipping when in gear even at idle. My first thought was something drastically wrong in to lower unit...
I drained the oil, which was clean with no metal (but did have a little water in it) so I tore it down anyways. Everything looks great with only normal wear for a motor its age. Bearings have no rough spots, bushings are tight, gears look great and the splined connections on the driveshaft are good. The clutch dog looks like new along with the water pump impeller. The only bad thing was all the fishing line wrapped up in the tailshaft seal which is undoubtably where the water came from... but back to my problem.
I just got my new seal kit today and haven't had a chance to throw it back together and trouble shoot farther. Now that I think about it, my next thought is that it could actually be a missfire. I'm used to working on car and truck engines and didn't consider the possibility that the long stroke of a 2 cycle missing could cause the motor to jump so hard, but that is my thought now. It starts and runs great but now I'm thinking that possibly under load when the spark killovolts spike up that it is enough to jump spark and ground out every now and then. I would think if it was a coil problem then it would just crap the bed and not be doing this intermittantly. It has full power but it just hammers every so often.
After I get it back together this weekend I plan to fire it up and get out the squirt bottle and see if it is jumping spark anywhere or carbon tracking down a plug or a loose magnet or something.
I was just curious if anyone else has had a similar problem or has some input on something I'm overlooking.
I drained the oil, which was clean with no metal (but did have a little water in it) so I tore it down anyways. Everything looks great with only normal wear for a motor its age. Bearings have no rough spots, bushings are tight, gears look great and the splined connections on the driveshaft are good. The clutch dog looks like new along with the water pump impeller. The only bad thing was all the fishing line wrapped up in the tailshaft seal which is undoubtably where the water came from... but back to my problem.
I just got my new seal kit today and haven't had a chance to throw it back together and trouble shoot farther. Now that I think about it, my next thought is that it could actually be a missfire. I'm used to working on car and truck engines and didn't consider the possibility that the long stroke of a 2 cycle missing could cause the motor to jump so hard, but that is my thought now. It starts and runs great but now I'm thinking that possibly under load when the spark killovolts spike up that it is enough to jump spark and ground out every now and then. I would think if it was a coil problem then it would just crap the bed and not be doing this intermittantly. It has full power but it just hammers every so often.
After I get it back together this weekend I plan to fire it up and get out the squirt bottle and see if it is jumping spark anywhere or carbon tracking down a plug or a loose magnet or something.
I was just curious if anyone else has had a similar problem or has some input on something I'm overlooking.
