Actually they'll handle very rich mixtures (4 stroking rich) with no problem at all. I got all brave and tested this out on a brand new ABC running slobbering rich for 45 minutes and the piston wasn't even marked let alone starting to run in. CL stunt ABC's are run in a continuous 4 stroke for hundreds of hours with no harm at all. It's an internet myth.

Enya 29/35's however never wear out .