These are the older single ring pistons. I've done a Poulan 54cc conversion. It runs great with ignition from RCIGN. I've got another 54cc Poulan that I've already cut up. I just need the ign. hub, carb adaptor, and mount.

I sent a 34cc Craftsman to Ralph. He's working on it now.

I feel pretty confident that I can do the Ryobi myself. I've already ordered an engine mount from a guy on Ebay. I'm going with the CH on this one. I talked to them yesterday. Really nice guys and very informative.

I'll try to move the reed valve limiter out a bit to improve performance. I've got a friend who is willing to deck the cylinder a little for me. I read somewhere that you can go up to .025" on the cylinder. I'll probably go a bit conservative there and only deck it about .015" I'm going to get ahold of Frank Bowman and get a new ring from him. CH sells a bigger carb for it, but I've read conflicting reports on the carb modification. One report says that if you want to swing a big power prop--like an 18-8; the you should stick with the stock carb and plan on running the engine at lower RPMs. The other report says that if you want to swing a smaller prop-- like a 16-8---then you should get the larger carb and let the engine run up to 8000RPMs or thereabouts.

I'll just run it with the stock 9mm carb for now and see how it likes a few different props. It will just depend on where I can get the most thrust and still have enough clearence to swing that particular prop.

Has anyone done anything with the exhaust port on these? I would think that if you were to shave .015" off the cylinder that you'd be loosing something on the exhaust port. The compression would go up- but you'd be changing the exhaust duration and timing by lowering the cylinder. I guess you'd just grind the top of the exhaust port out the same amount that you took off the cylinder?? Maybe a bit more

CH told me not to try and run it too hard. He told me that it would probably fly apart if I run it too hard and try to hop it up too much. After looking at the crank and connecting rod----I'd venture a guess that CH is right.