What a great motor/ pipe combo. Was running a SS .21 and JP-4 combo in my buggy and a SS .21 and JP-1 combo in my truggy. Put an R2 on both and was able to lean the buggy out 2 more hours and the truggy 3 hrs. Haven't checked runtime yet but it felt considerably longer (seat of the pants never lies LOL). Performance was increased on both before leaning them out. I'm a believer in this motor, I haven't found a better one for the money. Not even close. BTW, both of my pipes were missing the set screw for the pipe hanger, anybody else missing theirs?