"Cam.... There's no need t
"Cam.... There's no need to be using a 40/1 mixture. It's quite alright to use the standard 50/1 mixture for break in. The problem you describe would be contributed to a slightly clogged/fouled carburetor. Possibly, whoever rebuilt the engine did not do a thorough job of rebuilding the carb (it happens). I'm assuming that the compression and spark etc are as they should be.
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