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Tohatsu m90a wont start.

sejrsen

New member
Hi

My 2-stroke m90a EPTOL is not starting at the moment. Got the motor a year ago, and it would idle fine. Then when I would start it up this summer it would not run properly.

I noticed that one one the reed valves dit not close 100%, so I replaced all of them. Also rebuild carbs. Timing should be OK as well. And spark on all plugs.

Also sprayed Quicksilver powertune directly into cylinders from both intake and combustion side, because it is an old engine (1999). Perhaps that was a bad idea because now it wont start at all. When I crank only VERY load pops (like gun shots) happen every 5 secs or so.. What causes this? Could it be powertune in crankcase?

Compression is perfect for all 3 cylinders. And engine is on overall good condition.

Thanks
 
DeCarboning is usually done while the motor is running. If you have all that stuff in the crankcase, that's probably why it's not starting. After you get past that (lost of cranking), you may be OK.
 
Tried cranking and cranking with no luck.

Started to search the good old internet again.

Found a forum where a guy had a similar problem. Another guy suggested that the flywheel key had come apart. So the timing was all wrong.

Checked mine. Sure enough. Key was split vertically in 2 parts. Allthough the flywheel is not loose in any way and the flywheel nut is very secure. The flywheel can probably move a bit.

Have to find a new key. Will update.
 
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