I recently installed an HMF pipe and dynojet kit. My Rancher already had a K&N filter on it.

I installed the jet and needle groove recommended by the instructions.

Everything is fine WOT but sometimes under partial throttle the atv will sputter a little bit.

It has a 124 main jet, needle on 3rd groove, and the mixture screw was fully seated then turned back out exactly 3.5 turns.

Any ideas?

 

Try adjusting the mixture screw can be a lil different due to certain circumstances.

 

Go to the next size up jet.

 

But I thought the main jet mainly helped Wide Open Throttle?

Would changing the needle or "pilot" jet help for my low end problem?

 

Good point, after reading your post again, Im thinking it my be your air\mix. try 2.5 turns instead of 3.5. Also make sure you know your attitude? Google it to be sure

 

I'll try the screw.

Memphis alt. says 331ft above sea level, so I had that set right at <3000.

 

Call Dynajet tech line. They were very helpful, even called me back!!