Stan,

I think you will also find that this engine does improve after breakin. I ran a stock G26 on a Cermark Sukhoi which didn't seem to have the expected power and after switching to an Abel muffler it was a different and better performing plane. I know I'm not giving you any info on your specific model of plane but I sure wish I could. That looks to be a very nice aircraft. Try www.abellrc.com for a good muffler recommended by Ralph Cunningham.