What kind of Jet was in my 400???

[AZSCTACO]

Well....I am putting on my HMF s/o and EHS lid tonight on my 02' so yesterday I did the jetting and what I pulled out (main jet) was not like what I have seen in all these "how to" write ups. So I was curious what kind of jet it was.

It basically was 2 small brass looking jets that threaded into each other....and the one on the bottom had a 146 jetting number on it. The bike was stock when I bought it so why would someone put a 146 in it??? Sea level????

All I have read is that the 400ex comes with a 148 Keihin stock.

I was bugging out cause the lower piece had to be taken out with a screw driver. It wasn't a 6mm...it was round.

Thanks guys

[Honda#4]

Thats cus its a Dynojet main, they have a different numbering system than Keihin. Dynojet has an adapter then the main jet.

[AZSCTACO]

So if that is a dynojet jet at a 146....that means it is equal to a 160 main for a Keihin???? That is fat as hell for a stock 400ex isn't it????

[2004exrider]

Sounds to me like you pulled both the jet and the jet holder out. Honda did offer two different stock jets, one for high altitude and one for low.

Jimmy

[F-16Guy]

Yep, that was a DynoJet main with the adapter. It also has a special needle. If all you have is a slip-on, that should actually be pretty close for DJ jets; maybe one size up. If you want to go back to Keihin jets, you'll need to buy the correct needle. I have a whole DJ kit I'll sell you if you want it.

[AZSCTACO]

Well I installed the HMF s/o and put the 155 k main jet in and it seemed to run awesome. Would the bike not have ran right if there was a DJ needle??? Could the old owner just have changed the jets to DJ and left the needle alone??? Is that possible??

[F-16Guy]

I'm sure it wouldn't make a huge difference; they just have a slightly different taper. If it runs well, then call it good!!