K&N Air Filter + Dyno Jet Kit

[LazeR]

I recently just added a K&N Air Filter and a Dyno jet kit to my 2002 Honda 400ex, when i put in the jet kit it said to change to the dynojet needle putting the clip on the 3rd slot which i did then it said for under 3000 feet to put in a 142 jet...well i pulled the stock jet out and it was a 148!!! so im totally confused why i would be getting more air and less fuel?? or does the needle have something to do with that? also it had me put an adapter in first then the jet into the adapter. it seems to run fine and i could tell a nice change in power but i was wondering how i can actually tell if its running rich, lean or just right so i dont hurt my motor?

[wilkin250r]

A 148 Dyno jet and a 148 Keihin jet are not the same size jet.

[ewalker302]

Yeah a (DJ)146 is like 1 step bigger than a Stock 148.

I know it's screwey but thats true.

& why the hell don't they put a (DJ)148 jet in there???
This is how I could check out the jets.

4 me the 146 works good but still is slightly lean & the 150's too big.

Take your needle, stick it in the jet (reaaal easy like) & see how much bigger the different # jets are.

& just because I know somebodys gonna say this anyway,
be real careful & dont jack up the needle or jets, just be gentle with the hole, u know.

:bandit:

[LazeR]

OK thanx so now that i know that it shouldnt screw up my quad lol, is there anyway to tell wether im running rich or lean on a 4 stroke?! just look at the plug or what? thanx again for the help!

[cals400ex]

yep, take a look at the plug after you get some time on it. just remember, you will be getting plug readings from not only your mainjet, but your needle and your pilot jet too.

[ewalker302]

Im no expert, but i've read that its kind hard to adjust your jetting by the plug, cause of fuel additives & other reasons i've read here.

Rule of thumb:
for main

If it bogs---dosen't want to rev quick when u get back hard on the gas after leting off for like 1/2 second----rich

If you get backfiring on decel-----lean.

Then u can fine tune w/ the fuel screw - in---leaner, out---richer


& if it dont run right at 1/4 up to 3/4 throttle
adjust the needle clip pos - up---leaner, down---richer.


Hope this helps.

:bandit:

[LazeR]

alright i apreciate all the feedback.....since it started raining here a little bit i have access to a motocross track about ¼ mile from my house so i'll probably start riding it, and see if i got it jetted right

[LazeR]

Im hopefully going to ride my quad today to make sure im not running rich or lean......even if it seems to run fine should i try a bigger jet? and is there anything anyone else can add to help me :)