I have a 97 300ex it runs great but today I raced a guy with a 94 300ex who still had the stock air filter all he did was go 2 sizes bigger on the main jet and drill some holes in the air box lid he smokes me it was a drag race. evrything else was stock stock gearing everything. should I do the same and go 2 sizes bigger. I uasauly run with no air box lid what do U guys think???????/ remeber ride red ride SMART and ride hard!!!!!!!!!!!

 

It depends on which main jet you installed from the Dynojet kit. I think they give you a few options. You could try going 2 sizes bigger, race your friend, then try 2 sizes smaller and race again. I have found that Dynojet's jets are different sizes than Keihin's, so you want to make sure you get their jets.