I acquired a Fox .29 RC just like the one pictured. No matter what I did, I could not get it to run. It would start, running very rough and unable to throttle up, while spitting fuel out of the carburetor, then quit.
After trying many, many things, I finally took the engine apart and discovered the sleeve had been installed 180 degrees wrong... exhaust ports on intake, and visa versa!
The engine appeared to have never been run, so it is a mystery to me as to HOW this might have happened? Since Fox test ran all engines at the factory, again I wondered HOW..?
Anyway, after correctly positioning the cylinder sleeve, the engine started and ran very well.