what jet should i use

[exkid04]

my 400 is running rich and it has a 146 jet what one should i go to my bike has k&n filter, t-4 exhaust

[mojoe2878]

Originally posted by exkid04
my 400 is running rich and it has a 146 jet what one should i go to my bike has k&n filter, t-4 exhaust
are you sure its a 146?
has the needle clip been moved any?
i cant see how its running rich with a 146 in it, it should be way lean.
usually with your mods you would need to run around a 152 or 155 main jet

[exkid04]

Originally posted by mojoe2878
are you sure its a 146?
has the needle clip been moved any?
i cant see how its running rich with a 146 in it, it should be way lean.
usually with your mods you would need to run around a 152 or 155 main jet


yeah it said 146 on the main jet, the needle clip is in the stock position 3rd groove from top, my spark plug is really black, i put a 150 or a 152 i think

[LazeR]

I bet if its a 146 its a dynojet....i think the 142 is equal to a stock 148 kehein

[mojoe2878]

Originally posted by LazeR
I bet if its a 146 its a dynojet....i think the 142 is equal to a stock 148 kehein
yeah, if he has the dyno jets and not the kiehn jets like i thought then that would make a dig difference.
if you are running a dyno jet the did you use the dyno jet needle too?
what jets and needle do you have in your carb.?
if you have the dyno jets and needle then you may need to ethier go down 1 jet size or move the needl clip up 1 notch or put some keihn jets in there and go back with the stock needle.
you can also try running it with no air box lid and see if you will get enough air into it to compensate for the jetting you have now,

[exkid04]

i dont know what kind of jet it is but i think it is a keihin

[cals400ex]

what the jet round or hex shape?


i have a feeling your checking the plug exactly when your not supposed too. you need to check the plug right after you get done from a full throttle plug chop. so take the bike out and floor it. when you get to top speed hold it there for a couple seconds and quickly pull in the clutch and shut it off. now check the plug. if you check the plug after starting it it will probably be dark. this is from you giving it a rich jetting by either using the choke or pumping the gas for easier starting.

if your using a 146 keihin, your too lean unless your at really really high elevation levels. the stock mainjet is a kiehin 148.

[exkid04]

Originally posted by cals400ex
what the jet round or hex shape?


i have a feeling your checking the plug exactly when your not supposed too. you need to check the plug right after you get done from a full throttle plug chop. so take the bike out and floor it. when you get to top speed hold it there for a couple seconds and quickly pull in the clutch and shut it off. now check the plug. if you check the plug after starting it it will probably be dark. this is from you giving it a rich jetting by either using the choke or pumping the gas for easier starting.

if your using a 146 keihin, your too lean unless your at really really high elevation levels. the stock mainjet is a kiehin 148.

it will probably be a little bit before i can open it up cause the only place i have room to do that is out and the track on a island here and i still have to put my bike back together

[bdrue]

well u should do it if u weant it fixed. my bike has a slip on and a filter and i run a 150 main jet with a notch down on the needle and a 42 pilot at 4000 ft, but i also have the keihin jets (hex)