I'm at a loss on my jetting.. Please advise

[idro]

My only mods to the ATV is an HMF slip on exhaust. The rest is stock. 2 years ago the ATV ran fine with the stock 38 pilot jet, and 155 main jet.

Ok, i haven't ridden my ATV in over 2 years. I cleaned the carb, took it all apart needle and all. Replaced the gas. Replaced the oil and oil filter. Cleaned the air filter.

I went to put everything back together and it wouldn't idle or run still. Ok no biggie, fiddled with it for a bit. I got out my old dynojet jet kit and replaced the pilot jet to the 42 and i have the screw backed out 2 full turns. THe thing idles like a dream now.

Now on to WOT. THe thing would sputter at WOT and run terribly. Ok, i went up to a 160 and it got worse(HMF recommends 160 main jet on their website). So i backed down to a 152 main jet and the thing does great on WOT.

Now on to the mid range. I can't get the mid range right. I moved the needle up a notch trying to lean it out and still no dice. I did a plug run on the mid range and the spark plug is black as black can be. I'm still stumped. Anyone have any ideas?

[honda400ex2003]

raising the needle to the 4th will richen it up so going to slot number 2 from the top will lean it. (dropping the needle)

that should get you what you need.

steve

[idro]

I think i either got it on slot 2 or 3. Can't remember. I'll take it apart and double check. IF that doesnt work, should i go back to a 148 jet size??

[honda400ex2003]

id go to a 150 and 3.5 turns out with a 38 or 2.5 turns out with a 42 pilot with the 3rd notch on the needle and leave it.

steve

[dave07ex]

Are talking about DJ main sizes or Kehein main sizes?

[honda400ex2003]

keihin sizes are always my recommendations.

steve

[dave07ex]

If he's using a DJ 170, he's gonna be WAY rich. DJ 170 is something like 190 Kehein. HMF's 170 recommendation is likely a Kehein number, which is rich for just a slip on. honda400ex2003's recommendation sound about right to me.