Chris,

There's been a lot of discussion about the CL-only EVO 36s on some CL sites. Much comment that that engine, at least, prefers fuel with low or no castor oil in the fuel 'package.' Of course, a total oil percentage around 20% is indicated.

That engine reportedly likes to carry a bit more load than many "modern-metal" engines. (We often run CL Stunt engines at higher RPM on flatter pitch props, if the engine does better that way... The EVO 36 is said to want a bit more pitch and diameter. )

...Raises the question - what fuel are you using? Old fuel runs funny. Fuel for ABC/etc engines used in older iron engines may cause damage. Iron engine fuel in an ABC-etc. engine may have too much castor, and may gum up the the precise fit cut into it.

The other points to date - plugs and gaskets - may help a lot. The CL .36 may not be designed as nearly like you 46 as would have experience with it be useful for you... Just a few other areas to consider, if that's the situation.

Luck