ORIGINAL: buzzard bait
So what's the plane with the .65?
I liked my .20 on the test stand very much. Have not flown it yet. I used 22% oil, 1/2 castor, and broke it in with short rich runs, gradually getting leaner. It just got better and better. At the end, it would turn a 12x4 without any complaint.
And yes, the sound with the stock muffler is nice.
Jim
Your sportster would be even happier if you fed it all castor and no synthetic. Mine turns 400rpm faster on all castor vs. SIG Champion which is 50/50 blend. Thats with 25% castor to boot.
The front bushing on my .65 doesnt spew nearly as much oil as it used to on SIG fuel.