mower doesn't start when warm

[SGRIFF144]

The mower, L21ZPN, has been running awesome since an overhaul with one minor problem. When the mower is cold, it always starts on the second pull without any hesitation. However when I stop the mower to clean out the bag, it doesn't always restart. I've read that the coil may not function as well once the engine is warm. As a result, I checked the spark when restarting the engine was an issue and the mower appears to have good spark. Normally once the mower sits for several minutes I am able to restart the engine after several pulls...any thoughts?

On another note, I found a Lawnboy 7000 in the basement of my grandparents barn. From what I am able to find the mower dates as a 1956. The engine is stuck and I have read that they no longer make piston rings for the C engine, which I am assuming will need to be replaced. Is there anyway to find parts for these mowers or am I just out of luck?

Thanks
Sean

 

[MRCo.]

Maybe vapour locking is an issue, but it sounds like the coil. How did you test spark?

On the rings, trawl eBay or google a place with NOS parts.

 

[SGRIFF144]

I pulled the plug and grounded it against the crankcase then pulled the cord...I guess it's not really a definitive spark measurement