Bay Boater
Cadet
- Joined
- Aug 16, 2003
- Messages
- 17
Motor is a 50273C 1972 Lark with electric shift. I bought it used for a 16ft aluminum bowrider. I've had it out a bit - have put maybe 5-6 tanks of gas through it with no major problems until now.
I have had one minor problem - it came with the timing adjustment set so that there was almost no spark advance at full throttle. The guy who had this before me used it to push around a heavy 17 or 18 foot wooden boat. Just ran it around at hull speed. I wonder if his mechanic did this, retarded the timing, to keep from straining the motor too much. I know when I got it the paint on the block and head looked new and both cylinder compressions were in the 165 psi range.
I reset the timing advance link by guess and it ran much better and that?s where almost all my time has been with it. But I suspected I may have advanced the timing too much (seemed a little weak on low end torque) and one day I backed it off a little. I dropped the boat back in the water to try it out.
The motor never started. It usually kicked right up and idled easily. This time it would turn over OK, fire like one or two times, enough to disengage the starter, but would not run. On about the fourth or fifth try it locked right up. On the starter motor. No dragging down or anything. Turning free one second and stuck the next. I pulled the cover and tried turning the flywheel by hand. It would turn but something was dragging mightily. The starter would take it through a turn or two but that was it. I pulled it out of the water and came back home.
The flywheel will turn freely for maybe 140 degrees and is very stiff elsewhere (plugs out). The free range is centered on TDC of the bottom cylinder. I have peeked up the spark plug holes and see no issues with the cylinder walls. I needed the boat running for a trip two weeks from then so I pulled this motor off and put on a spare 40hp I have. This motor is still sitting in my garage.
What happened? Did I break a reed valve that got jammed in a bearing or intake port? Would the few times it's turned past the hard spot (maybe 6 or 8 times) have ruined a bearing or piston? I am wondering if the hard starting was because of a broken reed and it hung up when the reed migrated further in.
What are the odds I can save this or is it someone's parts motor now?
Thanks for any advice.
Bill
I have had one minor problem - it came with the timing adjustment set so that there was almost no spark advance at full throttle. The guy who had this before me used it to push around a heavy 17 or 18 foot wooden boat. Just ran it around at hull speed. I wonder if his mechanic did this, retarded the timing, to keep from straining the motor too much. I know when I got it the paint on the block and head looked new and both cylinder compressions were in the 165 psi range.
I reset the timing advance link by guess and it ran much better and that?s where almost all my time has been with it. But I suspected I may have advanced the timing too much (seemed a little weak on low end torque) and one day I backed it off a little. I dropped the boat back in the water to try it out.
The motor never started. It usually kicked right up and idled easily. This time it would turn over OK, fire like one or two times, enough to disengage the starter, but would not run. On about the fourth or fifth try it locked right up. On the starter motor. No dragging down or anything. Turning free one second and stuck the next. I pulled the cover and tried turning the flywheel by hand. It would turn but something was dragging mightily. The starter would take it through a turn or two but that was it. I pulled it out of the water and came back home.
The flywheel will turn freely for maybe 140 degrees and is very stiff elsewhere (plugs out). The free range is centered on TDC of the bottom cylinder. I have peeked up the spark plug holes and see no issues with the cylinder walls. I needed the boat running for a trip two weeks from then so I pulled this motor off and put on a spare 40hp I have. This motor is still sitting in my garage.
What happened? Did I break a reed valve that got jammed in a bearing or intake port? Would the few times it's turned past the hard spot (maybe 6 or 8 times) have ruined a bearing or piston? I am wondering if the hard starting was because of a broken reed and it hung up when the reed migrated further in.
What are the odds I can save this or is it someone's parts motor now?
Thanks for any advice.
Bill