i changed my main jets in my v-force. stock were 140r, 135f. i change them to 138r, 130f, is this ok, the only mod i have is a k&n.

 

Why would you jet leaner when you added a higher flow air filter? The V is a little rich from the factory but I would not lean the carbs out with the filter change, Do a couple nice runs and do a plug check and Im sure you will be fine with the jetting where it is at.

 

Did you replace with kehin or dynojets?

 

i dont know i have fmf jets.

 

should i put the 135 in the front instead of 130?

 

Hell ya you should.. if you were at 140/135, put in 145/140 and see how it is, if you only put a filter, and kept airbox the same, you might not even have to touch the jets, leave it at stock, and then see how it is..

 

Thats the problem. If you are replacing stock jets with FMF jets they are rated different. FMF jets are dynojets with FMF name on the package. Dynojets have a lower rating. Your stock setup of 140, 135 would be like a 126,122 in dynojet. when you changed you went to 138,130 dynojet and thats like 152,145 stock. It will probably be to rich for just an air filter.

 

This will help your situation. Text and by the way Kawasaki stock jets are keihin.