Bills, Thanks, And yeah, Im havin great time with this convertion! I think weve figured out this 2.3/16 is a 38cc with a 16in bar. My Geebee will est weight out with engine about 14lbs. Dont you think this engine will be enough? And what prop size should I start out with? By tuning and modifications, do you mean carb ajustments? What modifing can be done other than elect. ignition? Thanks! Al