quad sputters on accel

[jayblazer]

i have just gotten myself an 03 kfx that will sputter a little bit on acceleration it has an rs-3 yoshi pipe and a k&n air filter. im not sure what the jetting is on it but i pulled the plug and it looks like im running lean. any suggestions on jetting or other things to check. thanks

[mlrsone]

i had the same problem, and i went and changed my pilot from a 22.5 (stock) to a 25. but i also bought a 27.5 just in case i needed it. the 25 worked fine though

[drzoo2]

There is no way to help you without you opening the carb and finding out what the jetting actually is. Is the airbox lid on or off?

Look at the pilot, needle, and main.
z

[jayblazer]

ohh im going to open it up it was like 11:30 last night that i started this topic and i was going to tear it open tonight but i was hoping to get some good base lines for where to start.
btw the air box is stock and im running 93 octain.

[drzoo2]

The compression is low enough to run 87 so unless the gas is old it shouldn't matter. Have you tried taking the lid off quick to see if it helps. I may have been jetted for this and put back on when you got it. It won;t run right unless jetted for one or the other.

[cataway]

jayblazer
as you can see we would like to help but till you pull the carb and can tell us whats in it we will just be guessing .
so......... just to make a guess i would say your going to need a
142-145 main , a #25 pilot jet ,fuel screw 2-2 1/2 turns out, take off the air box lid (the whole air box off would be better but i under stand its the water thing )
if your going to run with out the spark arrester a bigger main jet will more than likely be needed.
in the mean time have you tired turning out the fuel screw 1/2 a turn ?

[jayblazer]

alright i took the carb apart and he had everything in there that the dynojet kit recomended but he only 2 1/2 turns out on the air screw i opened it up to 3 1/2 but i will have to wait to see how it runs cause it is raining hard as hell here now.
but for the record here is where im at.
dyno jets needle at the third setting
main jet is a 124
pilot is stock
and the fuel screw is 3 1/2 turnes out.
how does that sound with my stock air box, k&n filter, and RS-3
full system?

[cataway]

Originally posted by jayblazer
alright i took the carb apart and he had everything in there that the dynojet kit recomended but he only 2 1/2 turns out on the air screw i opened it up to 3 1/2 but i will have to wait to see how it runs cause it is raining hard as hell here now.
but for the record here is where im at.
dyno jets needle at the third setting
main jet is a 124
pilot is stock
and the fuel screw is 3 1/2 turnes out.
how does that sound with my stock air box, k&n filter, and RS-3
full system?
needle OK
a 124 jet is way small and very small if you run with out a air box lid , if your going to stick with DJ jets a 150 may work better, if you run with out the air box lid.
the pilot may work for you but more than likely your going to have to get a #25 pilot jet ,note ... do not turn the fuel screw out any more that 3 1/2 turns.

[drzoo2]

As stated above the 124DJ is way too small. Stock is Mikuni 130 and your putting in a 124DJ. Rule of thumb is DJ jets run about 10 points smaller than Mikuni jets. One is rated for flow and the other on hole size. A 140 DJ would be about the equivalent to a stock 130 Minkuni. Your way rich on your fuel screw.....unless you tuned it there.

z

[cataway]

http://www.arcticchat.com/forums/index.php?showtopic=11935

[jayblazer]

so basically dynojet is just wrong on there instructions. alright i will see how it runs tomorrow and we will go from there. i was really hoping to not have to take off the plastic and remove the carb. has anyone gotten a main jet in without taking the carb out completely? in that link the fuel mixture screw is in the middle of the the two bottom carb bowl screws right?

[cataway]

no you dont have to take off the fenders to get the carb off.
you will find the that carb bowl screws are hard to get out ,use a #2 Phillips a #1 Phillips will strip the heads ,after you get them out go to the hardware and get Allen head screws to replace them , get 7 as the screws on the throttle cable plate should be changed as well

[cataway]

Originally posted by jayblazer
so basically dynojet is just wrong on there instructions. alright i will see how it runs tomorrow and we will go from there. i was really hoping to not have to take off the plastic and remove the carb. has anyone gotten a main jet in without taking the carb out completely? in that link the fuel mixture screw is in the middle of the the two bottom carb bowl screws right?
http://i44.photobucket.com/albums/f9/cataway/Carb_Labeled.jpg

[cataway]

this compares jets of 3 different types of jets ,as you can see the hole is the same size but they are numbered differently
Width------Keihin # -- DynoJet # -- Mikuni #
0.0350---- 92.5--------- 92----------- 86.3
0.0360---- 95----------- 94----------- 88.1
0.0370---- 97.5--------- 96----------- 90.0
0.0380---- 100---------- 98----------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4
0.0510---- 132.5------- 124--------- 116.3
0.0520---- 135--------- 126--------- 118.1
0.0530---- 137.5------- 128--------- 120.0
0.0540---- 140--------- 130--------- 121.9
0.0550---- 142.5------- 132--------- 123.8
0.0560---- 145--------- 134--------- 125.6
0.0570---- 147.5------- 136--------- 127.5
0.0580---- 150--------- 138--------- 129.4
0.0590---- 152.5------- 140--------- 131.3
0.0600---- 155--------- 142--------- 133.1
0.0610---- 157.5------- 144--------- 135.0
0.0620---- 160--------- 146--------- 136.9
0.0630---- 162.5------- 148--------- 138.8
0.0640---- 165--------- 150--------- 140.6
0.0650---- 167.5------- 152--------- 142.5
0.0660---- 170--------- 154--------- 144.4
0.0670---- 172.5------- 156--------- 146.3
0.0680---- 175--------- 158--------- 148.1
0.0690---- 177.5------- 160--------- 150.0
0.0700---- 180--------- 162--------- 151.9
0.0710---- 182.5------- 164--------- 153.8
0.0720---- 185--------- 166--------- 155.6
0.0730---- 187.5------- 168--------- 157.5
0.0740---- 190--------- 170--------- 159.4
0.0750---- 192.5------- 172--------- 161.3
0.0760---- 195--------- 174--------- 163.1
0.0770---- 197.5------- 176--------- 165.0
0.0780---- 200--------- 178--------- 166.9
0.0790---- 202.5------- 180--------- 168.8
0.0800---- 205--------- 182--------- 170.6
0.0810---- 207.5------- 184--------- 172.5
0.0820---- 210--------- 186--------- 174.4
0.0830---- 212.5------- 188--------- 176.3
0.0840---- 215--------- 190--------- 178.1
0.0850---- 217.5------- 192--------- 180.0
0.0860---- 220--------- 194--------- 181.9
0.0870---- 222.5------- 196--------- 183.7
0.0880---- 225--------- 198--------- 185.6
0.0890---- 227.5------- 200--------- 187.5

[jayblazer]

alright well i took it for a spin and it is running great pulled hard the whole time with no sputter so the dynojet kit seems to be close. but if i remember right if you guys are correct im running way to lean am i risking damage? should i do plug tests? or just switch jets. one more thing worth mentioning is that i am at sea level.

[cataway]

how well does it run with the air box lid off ?