ORIGINAL: earlwb
As far as I am concerned is that Fox makes perfectly good sport engines. They ceded the racing and competition engine business to other companies. It would be terribly difficult to compete with Jett or other companies like that. The Fox .35X combat engines was their last foray into competition types of engines. But if people want a competition engine for racing or speed or something, they probably ought to look for a different brand engine then, say from Jett for example. Of course with the 2.5cc engine market there are several all out competition engines, such as Cyclon, Fora, Parra for example. It is hard to compete with them.
Well, I'd go a little later than that. The Mark VII was pretty competitive, John Lowry ran one in Slow Rat at a Nats, can't remember what year, the very end of the 90s IIRC. He said the only non-Fox part on it was the plug (he used a Nelson plug). He said he put up the best time in the competition, too.
Iskandar