I have a KFX400, it started sputtering and pulling hard, it was still under warranty so I had it looked at and was told it was in the Carb but warranty would not cover it. The carb has been completly taken apart, replaced all the little rings, cleaned it out, and now it won't start at all unless you feed it gas directly. What I am trying to figure out is if it would be better to have the carb re-built or to get a new carb. If I go with a new carb what is the best to run, easiest to install and does not take a rocket scientest to adjust?

 

Whoever did the disassemblying/cleaning the original carb did not do a good job. Either the pilot circuit got restricted by debris or the pilot adjustment got messed up. If there is no actual damage to the original carb, getting a new carb doesn't make a sense when it is so expensive (a few hundred $$). New carb is usually adjusted to the spec but you should check it before installing on the quad. It's a single carb and should be really easy. But if this is your first time working on carb, at least get a manual and/or help.