A practical suggestion: After testing and using about 50 plugs in the last several years I do not buy and use anymore
anyone else than the F type of OS. It is a 4 stroke plug which is similar to temperature to OS8 but the major difference
is that is very innert, meaning keeps its temperature longer due to the more massive spiral, as it should be for 4S.
This has many positive efffects and mainly: - more stable RPM at any fuel and as well much longer life although is
a bit more expensive. It is worth trying one prior buying many other types.
http://www3.towerhobbies.com/cgi-bin...&I=LXCB28&P=ML