I noticed the specs for this engine on the link that jymz provided. It says the rpm range is 2000 to 7400 on a 16x8 prop. I was getting about 6700 rpm on a 17x6 so that isn't too out of line. I was going to try a 16x8 and found I didn't have one on hand. Placed another order to Tower. Will try the Xoar 16x8 in a few days when it arrives and report the rpm's.

Now I know the engine is 21cc. I'm sure the previous owner said he thought it was a 26cc engine but he couldn't identify it and it was his best guess. I must say this engine runs much quieter than any of my other gassers in that cc range. I'm looking forward to getting this plane operational.

Thanks to all.

Mike.