Dyno Jets for HMF full system(400ex)Virginia...?

[660r2a400ex]

i live in va.80-90 degree weather for summer time. bike has got HMF full system, UNI air filter no lid, degree key, rev box and no snorkel. what jets are you using out of the dyno jet kit? is the smaller the jet better? will u get more performance out of a smaller jet? how can i tune my bike in to get the most hp gains out of this full system ? let me know what u guys are running with the hmf full systems

[atl_josh]

I have a full wb e-series exhaust and I have a dyno jet kit, and I put the 150 in and mine backfires flames sometimes when it is realy hot. I dont know if it is good but it is fast. It is also realy loud. I think I might have to go lower. I am trying to get help on mine :)

[SPODEBOY]

I just went through this. The HMF is an awesome addition. It really wakes up the bike. I went with kehin jets, a 158 main, and a 42 slow jet. That will do it.
-Spode.

[cals400ex]

Originally posted by atl_josh
I have a full wb e-series exhaust and I have a dyno jet kit, and I put the 150 in and mine backfires flames sometimes when it is realy hot. I dont know if it is good but it is fast. It is also realy loud. I think I might have to go lower. I am trying to get help on mine :)


you just need to increase the pilot jet size and/or turn the fuel skrew out some.


if your using keihin jets and just have a slip on, go with a 152 or 155 in most cases.