400ex Jetting question

[RiderTRX400ex]

i started out with a dynojet kit with a 146 main jet, ( following the instructions ) a week or 2 later i checked the plug and it showed it was running lean. I put a 160 main jet in and the plug still shows it is running lean, but it acts as though its running rich. when i wheelie and pump the throttle to keep my balance it seems that there is a lot of lag in the throttle response.. When i changed jets, there is a nut on some brass piece that the needle slides into??, the jets hang below this... That nut turned and switched the height on that piece that the needle slides into... could that be what is causing my problem?? I dont know what that brass part is or does and dont know what it should be at... I am running a Niks Pro X piston.20 over, Hotcam stage 1, E series slip, K&N FIlter in stock airbox....

ive checked the plug 4 times after putting the 160 in.. its been black (rich) white, blackish, and white.... its weird

any help or suggestions would be a help... THX

[RiderTRX400ex]

Note : i still got stock pilot jet too... Should I chage that out and if so to what size??

[cals400ex]

well, black is rich not lean. you need to check the plug after a full throttle run. get up to top speed and quickly pull in the clutch and shut the bike off. roll to a stop and then check the plug. a 160 DJ should be a fairly good starting point. what needle clip you at? i would probably run a 42 pilot jet.

[RiderTRX400ex]

i checked the plug after a to the bar run for 10 seconds at least, and it was whiteish, not gray or anything... it acts as though it runs rich, but the plug shows its lean... weird... should the pilot jet help ?? the needle clip is on the 3rd position down from the top i think, set it to the altitude according to the dynojet instructions... does the dynojet kit come with a pilot jet? Have to check it out...
Thanks cal

[cals400ex]

if the plugs are a gray or a light tan, it should be fine. however, the gas is different these days and it is hard to do plug chops. i kind of know how my bike runs and know what my plug looks like at these times, when using the same fuel, so i can adjust here and there. i really can't help much with the dynojet kits. i have never used them.

the kit doesn't come with a pilot jet. the pilot jet sits right by the mainjet.

i would think around a 160 should be close. i can't tell you on the needle because i have never tried that needle. i know you also have a possibility of putting a washer under the needle to make more adjustments.


the piece that mainjet screws into is called the needle jet holder. this piece must be adjusted right, when using keihin jets anyways. i know dynojets are smaller but have an adaptor so i don't know how this changes the overall length of the jet. when you screw the needle jet holder in, lock the nut down so that you can see 2-3 threads on the needle jet holder itself. this is when the nut is tight in place. you see what i am saying?

[schootar]

Follow Cal's advice.

I run DynoJets in my EX. It is a stock 400 with K&N, no airbox lid, no choke, 42 pilot jet and an E-series slip-on. I was running a 165 and it ran great. I recently put in a 170 and it's running rich. All my settings are per the instructions, except the main jet size. Go back over the instructions. The jet adapter may be off a bit. As Cal said, you should be pretty close with the 160 jet.

Look into putting a 42 pilot jet in it also.

[RiderTRX400ex]

Yup, i set my needle jet holder 2-3 threads out, and put a 155 main in to see how it goes. It goes a lot better than it did before and i only tried it for about 5 minutes... but ill try to check the plug tomorrow or something... Thanks for the right settings cal for the needle jet holder, thats what I needed...Yea im looking to get a 42 pilot... where can i get that, froma honda shop? if its easier to order it for the carb.. tel me the model of the carb or somethinglol....thanks guys:cool:

[cals400ex]

here is the part number to the pilot jet you need:

99103-420-0420