The following were recorded at sealevel - 72 deg. - 15% nitro (cool power)
10 X 6 - 12,200
11 X 4 - 12,800

Thanks for the numbers. What brand of props did you run?

I need to re-break in my Silverline .40; I just installed brand new piston, ring, connecting rod and bearings.

I'll post some rpm figures after a few tanks of running it rich.

BTW, the OS E-3030 mufflers make them super quiet and are a perfect fit.

Pictured are my Silverline and Blackhead

David