I just got a boxer 60 with an OS 61 pumped engine and am wondering what the best prop size may be, thanks for any info

I would suggest starting with an 11 X 9 on up to a 11 X 10 or a 12 X 8 or 9 or 10. You want to keep the rpm's in the mid to high 9's. The prop that will provide the best vertical is what you will want, and you can use throttle management in your straight line and down line flying. You didn't mention if this was a long stroke engine. If it is a long stroke, you can probably increase the length of the suggested props by one inch. Hope this helps.
GPB

Or if it has a red head and is a Hanno Special, then you want 12 x12, 12.5 x 11.5. I say this because there was recently a Boxer for sale with a Hanno, and I wondered if that is your plane.

Hi,
Thanks for the info, mine isnt the hanno special I am not too familiar with the boxer, was it ever a kit or just scratch built from plans, thanks

I just finished building a Boxer .60 this past fall. Mine has yet to be flown. It has an OS .60fx for power ,and Dave Brown retracts. As far as I know there was never a kit. Plans are still available.

Jim