RCU Forums - View Single Post - CMP Piper Cub 91" W / Satio 1.25 gas conversion
Old 06-22-2017, 02:30 PM
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Originally Posted by beachsideflyer View Post
Are you running two stroke oil premix in the Saito?
Yes, at 15:1.

I have had a mishap however and broke the big end of the rod but do not know specifically why.The engine had been inspected after the 6th flight and all was well and the engine was being well lubricated and the big end was good. It broke right after takeoff on the 9th flight after reaching altitude and cutting the throttle to cruise. Neither crank pin or rod was scored and the cylinder remains good.

Though the bearings didn't feel bad in place, they were replaced and the back bearing after being cleaned up did sometimes chatter when spun. The suspect is bearing chatter fatigued the big end. The engine was run on glow for five years and had sit up for five and the bearings had some rust. It does not appear to be a lubrication issue.

At any rate, it is back together for another go and has two flights since. I did shim the jug .013 to drop the compression. We'll see.