Trouble starting 100...
 

Well I am still having trouble starting my 100...

First problem is if you stop cranking close to the compression stroke, the starter won't turn the motor over...starter, battery ??? not sure

Second problem is after cranking and cranking and cranking, engine will fire and run like a top for 10 seconds and then just stop like it has not spark...??

All I have done up to this point is change the plug. No help with starting...

:bash2:

Clean all of your grounds.

I would suggest a new coil or a coil you know for a fact is working on a running cub. Second, check the timing and points. That is how my 1250 acted and had to get a new coil.. I am sure more guys will have some great advice too.

check the wire running out from your points cover. i know on my 122 it was bare and when it rubbed on something it would shut the motor off.

How about a bad s/g belt? Your not to crank the s/g for no more than 30 seconds. I'll agree, clean up the grounds, see what happens. compression, spark, and fuel are the requirements.