I just recived my HMF Sport complete exhaust I have a 2002 honda 400ex and i mostly ride in wide open areas or trails. I was wondering what jetting I should I use for my new pipe???IF ANYONE KNOWS PLEASE HELP!!!

 

You didnt order a jet kit when you ordered your exhaust???

Starting point with a full exhaust with no other mods would be to use a 158 or 160.

Every engine will require something different even if your buddy next door has the same setup sometimes. You have to test and tune. Manuafacturers can recommend base settings, but only you can jet your carb. More times than not, unless you have an airfilter or airbox mod, a 155 or 158 does the job.

After that, and only after that...try moving your clip down on the needle by one notch.

When fooling with carb settings and adjustemnts, always do one thing at a time and keep track of your changes in case you run into a condiditon that the engine runs worse....that way you know exactly how to go back to your other settings.

 

NOBODY in their right mind would buy a jet kit with their pipe when you can go to a dealer and get a handful of jets for all situations for about 1/2 to 1/4 the price. Trust a man who's done both. I got a Dynojet kit right after buying my HMF pipe, and soon after my engine informed me that it wasn't happy with Dynojet's ideas on the matter of fuel mixture. The solution for a person like me in that situation was to fetch some Kehlin jets from the dealer and do it the right way-by myself with parts actually meant for the carbuerator. (as opposed to Dynojet's "make one jet fit all carbs" solution)

 

Thats what happens when you mismatch brands and componets.....The HMF jet kit isn't but $15.00

The DynoJet kit isnt even a kit you need for just for changin the pipe.

 

Toss that jet kit in the trash and go to your dealer and get oem jets for a few bucks. You"ll be glad you did.