somethin for all (curious?)

[zlam27]

first of all, how does my jetting sound..
01' 400ex - choke and airbox lid removed, K&N, pro circuit T-4 slip-on..... 42 pilot/158main

i had a 160 dynojet in it and it actually seemed to run slightly better (i was using the stock needle though, anyone have a dynojet needle they wanna sell??)

heres my main ?......
when i took the main out today and changed to the 158 (keihn jet), the whole needle jet came out with it. it is threaded and there is a little nut on it to lock it in place. im wondering where that nut should be and what is the purpose of the threading..... anyone know what im talking about and where that should be adjusted to? i think i might get a keihn(sp?) 160 and put that in. i havent pulled the plug to see whats goin on, but i should be close on jetting. the elevation here is about 750ft and its about 85 + or - five or ten degrees.

sorry this is gettin long, if you made it this far then i hope you can help me out. i just read a dirtwheels article from a while back where they had my exact setup without the choke removed and 700ft higher in elevation - they ran a 155main. any thoughts.

zach

[sparks400]

i dont kno about ur bolt prob. but with my list below i run a 170 dynojet main and my plug is perfect, and im also below 3000ft heres dynojets jetting chart for the 400ex ( u need acrobat reader to run this page) http://www.dynojet.com/pdf/Q107.pdf

[H440exconfused]

Originally posted by zlam27
first of all, how does my jetting sound..
01' 400ex - choke and airbox lid removed, K&N, pro circuit T-4 slip-on..... 42 pilot/158main

i had a 160 dynojet in it and it actually seemed to run slightly better (i was using the stock needle though, anyone have a dynojet needle they wanna sell??)

heres my main ?......
when i took the main out today and changed to the 158 (keihn jet), the whole needle jet came out with it. it is threaded and there is a little nut on it to lock it in place. im wondering where that nut should be and what is the purpose of the threading..... anyone know what im talking about and where that should be adjusted to? i think i might get a keihn(sp?) 160 and put that in. i havent pulled the plug to see whats goin on, but i should be close on jetting. the elevation here is about 750ft and its about 85 + or - five or ten degrees.


The needle jet cannot come out the bottom, it comes out and adjusts from removing top of carb, butt you are referring to the sleeve that surrounds the needle that the jet screws into, if you change your jets alot you may have gotton your jet tighter than that tube so when you unscrewed it the whole assy came out, there is also a little brass ferrel that sits on top of that sleeve.the not is just a lock nut by the way, you tighten the tube down all the way then lock the locknut. You should just take the bowl off to put it back on though, not really a problem


By the way your jetting sounds good.

sorry this is gettin long, if you made it this far then i hope you can help me out. i just read a dirtwheels article from a while back where they had my exact setup without the choke removed and 700ft higher in elevation - they ran a 155main. any thoughts.

zach

[zlam27]

so what is everyone thinking? should i go get a 160 main? i tried holding it W/O and then letting off a little and seeing if it had a little more power (its one jetting technique explained on a post a few days ago) but it didnt seem to do anything. i guess ill go tinker and maybe check my plug.

zach

[cals400ex]

that needle jet makes a big differece if it is set wrong!! i would think that a 158 should be perfect. a dynojet 160 should be big. a dynojet 160 is approximately a keihin 162. i would first get a new plug. when doing plug chops, remember you need to stay at full throttle for a while because your plug will have readings at less than full throttle such as: there will be readings on your plug from your needle and position, pilot jet, fuel skrew, and main jet. as for the needle jet, don't skrew it all the way in!!! the bike will run slow. with the locking nut tightened all the way down, you should see about 4 threads on the needle jet. this is how i find it to work pretty good. when you do this, i would make sure you take the carb off so you can see better. if you have any questions, make another post and i will explain the best i can.

[zlam27]

hey cal, thank you so much for the help. i took the carb out and tightened that needle down as far as it would go by itself, then locked that nut to hold it. i dont know how many threads are showing exactly (didnt think to check) - but i know there were a few (i would guess between 1 and 3).

when you said it would run slow.....
i took it out that afternoon and the throttle response was kinda crappy. it didnt have the snap it did before (with the 160dj and the needle in the place before i adjusted it). read my new post if you get a chance.

let me know what you think.

zach

[cals400ex]

i already replied to your other post. i would just make sure you count those threads on the needle jet. put it this way: i gained more power by moving the needle jet down(unskrewing it) so you can count 4 threads than my curtis sparks x-6 pipe made!! i consider that to be a decent gain.