Bought a yoshi pipe for my kfx 400 and it recommends a 122.5 main jet, does anyone know what the stock mainjet is and do you think 122.5 is a good size for the yoshi stainless???? I don't know much about the jetting of carbs, I was told with a yoshi pipe I should use a 160 main jet. Any response would be helpful.....

 

this is not really bout ur question, but I just figured that you should know the Yoshi pipes rock! I have a full Team Suzuki system, which is made specifically for the KFX/z 400 engine.. but the Yoshi line rocks. Good choise man, and I hope you find the info ur looking for.

 

I had a white brothers race system on my KFX. It called for a 160 main as well. But thats only if you are leaving the air box lid off. I had no intentions of doing that so I wound up putting in a 138 and playing with the needle.