These are for the .61's ABC,and ringed. (FSR's)
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............disp........bore....stroke....hp....rp m......weight.
ABC..... 9.95cc.... 24.0 ....22.0 ....1.8@17K ....533 gr.
Ring.... 9.95cc.... 24.0 ....22.0 ....1.7@17K ....531 gr.

ABC practical rpm 2,000-17,000
Ringed practical rpm 2,000-16,000

They don't give the compression....(secret)....

The older .60 FSR is pretty much the same specs....
....only the prop stud is 1/4", and the .61's are 5/16.

Look what's on the back of this poster, in the carbs....