If so, I will throw a Tower/Hobbico $13 muffler on it.... That stock one would be a better PAPER WEIGHT!

I did not want to get the Ultrathrust muffler because of the price, but if the Tower muffler fits

Also, I am running this on an Ultrasport 40 what is a good "speed-prop." for the Irvine (11 x 7)? I am used to 12 x 4's and what not for fun-fly style flying...

Thanks in advance!
james

My .51 had exactly the same mounting/muffler dimensions as my .46FX.

I've been told that the Tower .46 muffler works well with the Irvine .53. In fact I bought one, but alas -- I have not mounted it yet on my Irvine .53...

I thnk the Irvine has the same dimensions as the .46FC.
I have one mounted on a Cloud dancer and it's an amazing engine. I have a 11x7 and it hauls like crazy, If yu want all out speed try a 11x8 or 11x9 if you want speed ans traction try teh 11x7 or 12x6
Regards,
Patrick