[What kind of Jet was in my 400???] - ATV Riders Forums - Honda, Yamaha, Suzuki, Kawasaki, Polaris, CanAm, Arctic Cat, Kymco ATVs

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What kind of Jet was in my 400???
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Posted by: 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

Posted by: Honda#4

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

Posted by: 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????

Posted by: 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

Posted by: 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.

Posted by: 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??

Posted by: 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!!