Mike, the Laser pictured is a .70, I run it on Fox 5% fuel with 20% 50/50 syn/castor blend. I do indeed have an Irvine 40 Diesel as well as a Q40. The Diesel and the Q have a few thousandths inch smaller bore than the standard 40 but have the .46 crank. AMB also has at least one 40D.
PS, I used to have a Laser 1.80 V-twin but sold it last year, it howled like a Chevy V8 when at full song.

The 40D is wearing an MVVS 3245 muffler I got from Dar. The prop is louder than the exhaust.