MS-39

[Geer Pyron]

I’ve been fighting with this little motor for awhile now and so figure it’s time to ask for help.
I’ve taken it apart and cleaned it.
I’ve got good spark (3/8” in air).
I’ve cleaned and blown the carburetor and have good fuel flow.
I have 80 psi compression.
I can get it to fire, even run briefly (3 seconds).
Is it true that these little motors need 110-120 psi compression?
If so, I guess that is my problem.
If that is my problem, how can I get the compression up?
Can I get it up with new rings?
The ones in there are not stuck at all.
Also, head gasket? Can one buy one still and from whom?
I made one, and it holds the 80 pounds compression, but I’d like to get a real one.
Thank you for any suggestions and help.
Geer
PS No, it doesn’t have the spark plug cover. Dang it!

JMGP

[Mumbles]

Before installing new rings, the cylinder should be measured for taper and out of round. If it is worn oval or egg shaped, new rings will be a waste as they will never seat to the cylinder wall. One thing you can try doing is run a heavier oil mix to see if it runs any better. The oil in the fuel is what seals the motor up and it just might help.

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