300ex jetting

[ABM-Cannibal]

What is the stock jet in a 1993 300ex? Also, what jet size do you recommend? I am at 5200' and have a HMF slip on with air box lid removed w/Twin Air filter. Engine is stock and so is the header.

[300exOH]

Stock main is 122. You may want to post in the HMF engineering section to get jetting answers. I am running a 135 main with a Sparks X4, UNI filter and an open airbox. I am around sea level though. I'm thinking you may want to start with a 128 and check the plug.

[tolson]

i have a 2002 300ex, no engine mods, a white bros e-series, k&n filter and no air box mods. 125 on the main seems to working fine.:)