Out of 6 or 8 ryobi engines i have one that has 2 thin compression rings insted of the 1 thicker ring. I have not used one of Frank's rings but the twin ring, no slitt cylinder, large crank case and short shaft has 3 times the compression as the single ring in the same set up. Is this a coman piston are a rare find? It is the only one I have ever seen.


I will try to let you know about performance when I get that info.
PS It came out of a Lawn boy trimer. I also got a small crank case engine out of a Lawn Boy.