Dynojet question...

[BigBadJ-400ex]

I'm getting a dynojet kit in a day or two and have a question....I have a stock 400ex with a k&n air filter and a HMF slip-on. What size jet do I need to use? HMF recommends a 175 main
but that sounds too big to me..Anyone with a similar setup? I live in Tennessee, don't know what my elevation is..
Let me know what you guys think........J

[phebus]

I wouldn't spend the extra money on a Dynojet kit. You could buy a few Keihin jets, and save a lot of money, and with the advice of this site, you get get it dialed in fairly easily. Just ask Cal, he is great with carbs.

[BigBadJ-400ex]

Thanks but it's bought and paid for...Just waitin' on the mailman.Any ideas on what size I need to run....J

[hondarider2006]

the largest jet in the kit is a 170, so start with that and work your way down. Just keep doing plug tests everytime you change your jets. It will tell you to start with a 146, and when I did that my plug was white as snow:eek2: Pretty much its all guess and check, there really isn't "one set jet" for each certain set up, each quad veries. Good luck man!!

[dsheola]

I use to run a 150 main with a 45? or 50? pilot on my 400 with a e series slip on
i don't think its much different for a HMF slip on
sorry you bought that dynojet kit. it really is a waste. too many jets that you will never use.

[hondarider2006]

Originally posted by dsheola
I use to run a 45 or 50? pilot on my 400 with a e series slip




:eek2: You sure it wasn't a 42:confused: :huh

[dsheola]

pretty sure it was a 45... i don't have it anymore so i don't know...
i remember i looked at the jetting the guy did on the 400ex with the e series on this site and went bigger because i also have no airbox lid, i have a outwears air box cover instead... also a 42-45 really won't be noticeable. I run a 170 main with a 50 pilot now with my lrd full system and it seems to be working great.

[cals400ex]

just a note:
dynojets and keihin jets have a different numbering technique. so, a 150 keihin is NOT the same as a 150 dynojet. when hmf says to use a 175, they are referring to a keihin 175. however, that is way too big in my opinion. if you put that in your bike it won't be as quick as it should be.

with they dynojet kit, i have seen some wild numbers flying around here. i could help you get the keihins dialed in, but i have never tried a dynojet kit so i am not positive. i have talked to people that said they thought there piped 400ex was lean with a dynojet 170. others said they had it pretty good and dialed in with a 146. if it was me, i have a feeling that one to two sizes larger than the 146 would be pretty close to where i "prefer" my jetting. good luck