Engine and jetting help!!!!

[tricked400ex]

Ok i recently put a ned hmf slip on exhaust on my 400ex. on the HMF site it says to use a 175 main jet, and move the pin to the third fromn the bottom also three turns out on the air fuel screw. Well thats al done to spec but my when i punch the throttle and at the high end of the throttle it sputters and dont wanna have it. Sounds like it is bogging down from to much gas or to little. I am going to pull the plug tomorrow to see if it shows and sign of running lean or rich. ANY SUGGESTIONS! all help is appreciated.

[northeast400]

It sounds as if you are way rich. HMF pipes are great but I don't know where they get their jetting specs from. They think a full system needs a 200!!!! Try a 160 or 155.

[Jingle #11]

i did what they said and it was crap. I use a 165 mj. the needle for me is great and the air/fuel is at like 2.5 on mine and its still a little rich.

[cals400ex]

with a slip on a 152 in summer and 155 in winter worked best here. this was with a K&N with the air box lid on.

we are at 625 feet above sea level.