I would have to agree that the engine would produce more realistic results at running temps.
I also agree about the carb being open, which in my previous testing the carbs were closed. I didnt even think about opening them.
My current desire is to be able to uncover a defective engine based on compression. I have a new MT-12 that did not have the tight fit that my previous MT engines have shown. While it seems to run fine, it bothers me that the fit is not very tight.
I do also have a O.S .46fx that fails to prime and hold fuel in the carb. It has had about 3 gallons through it and some lean runs, I suspect the piston and sleeve to be worn out, it will soon be on its way to Hobby Services. I do have a new .46fx to compare it to but have not broken it in yet.

I am just in from work and about to sit down to some dinner, I will do some more testing later tonight and post my findings.

Thanks for all the info,

Dbow