HMF Jetting on an '07

[liv4raceday007]

I have an '07 400ex and am going to be installing a slip on HMf pipe this weekend. I have the pipe and purchased the HMF jetting kit for it.

I'm just wondering how important it is to jet the quad after putting the pipe on. I know a lot of people have the HMF sport series pipe, so I was hoping someone would have an answer. Also, I have read that in order to re-jet, I must remove the carb, gas tank and some plastic as well. I have never re-jetted a quad before so any advice would be really appreciated!

Sorry if there is another thread just like this, I did try searching, but couldn't find my exact question

Thanks Guys!

[honda400ex2003]

I think those are dyno jet style jets so a 138 and 3 turns out on the f/a screw. If it is keihin style hex ones then go with a 150. You should not have to remove the carb but it is up to you. you would have to take the tank off and the side panels at the very least, that is how I do mine all the time. That jetting should get you close anyway. lol. It will depend on your altitude and if you have a filter or not. steve

[liv4raceday007]

On HM'F's site they recommend either a 165 or 170 hex, so I think I'll try the 165 first, right? As far as elevation, it will spend most of the time being ridden in northern Michigan. Is it a major project to remove the tank? I'm going to try to get it done here, but how much time should be set aside?

[woodsridn400]

any thing else done on the quad? i have sparks 6 degree key and k and n filter full hmf exhaust and only using 160 main and 40 pilot jet. id recomend you doing 40 pilot and 150 to 155. the site is way off in my opinion.

[liv4raceday007]

Nothing else. The quad is completely stock, and the pipe is just a slip on, not the entire system. Sadly I didn't get around to putting it on this weekend.