250x problem

[bigjeep310]

With air filter off runs perfect, will air filter on it goes to hell. Any suggestions ?

Jetting?



I have a cobra pipe and uni filter stock everything else

[400ex men]

go down on the M jet a lil bit try that:)

[bigjeep310]

Like what size would you say ?

Do you think that will solve the problem ?

[stonerider250x]

what is your main jet at now?.....and when was the last time u cleaned the filter...if the filter is clogged all up that could cause a problem also

[300ex-boy]

CLEAN THE FILTER! :D

[bigjeep310]

Just been cleaned !

How can I determine which main jet is in there? sorry dont know these little things

[stonerider250x]

u have to take the jet out the carb and it will say on the side

[bigjeep310]

Ok thanks alot Ill pull it out and see what it is .


Then Ill check back with ya.

One more thing I dont know if this a problem but I pulled my plug out and its got a lot of black carbon on it ?????

[BigDaddyCMU]

Yeah that means it's too rich. On the bottom of the bowl there's a plug that comes out. Inside is the main jet. If you don't have a main jet wrench, you can use a 6mm socket. The size of the jet is printed on the side. Depending on your mods, you should run either a 122, 125, or 128, unless it's heavily modified.

[stonerider250x]

what mods are done to it? cuz that can help decide if it rich or lean cuz my x is highly moded and im runnin a higher main jet that most pll do in their 400's. but i also have a aftermarket carb.