I used a micro-set of drill bits on my honda recon, just took the main jet off, drilled it one size bigger by hand and replaced it, ran perfect. but thats the cheapest and not always the best.

 

Jets are only a few bucks a piece, and using a drill bit does not allow the fuel to be delivered in the most efficient manner.

 

Run your machine and pull your plug. A white color indicates lean,, black is to rich. A light tan is what you want. You change this by your main jet inside the float bowl. Bigger number , larger jet. For acceleration on take off, your main needle ( inside throttle slide ) can be altered by lowering the e-clip up or down. Raising the clip will go lean. Move it until you get a crisp rev. I hope this info will help you. Also, a Dyno jet kit I would reccommend.........

 

i did find a vid on you tube its called fast jetting you YFZ but i didnt like it to much it didnt go into a whole lot of detail it just showed them changing the main jet... But how do i know what jet to replace it with??? Can someone tell me how jet sizes work

 

By the way guys i appreciate all the info!! I hope you guys dont think im a dumba*ss but when it comes to jetting im clueless until i learn

 

The jets sized are the holes thru which the gas is sprayed. The pilot jet is for low range. The main jet kicks in at mid range. Did you read the link in my previous post?