2002 cr250 jetting?

[shady02]

I have on 02 cr250 with pro circuit pipe and silencer. I also have boysen rad valve and milled cylinder head. I am running a 330 main jet at about 3000-4000 ft. I have excessive spooge coming out of my silecer and where my silencer and pipe hook together. Any reccomendations?

 

[elcamino12sec]

I would make sure that is the proper jet size. I dont have a cr 250, but the main jet size in my 1994 kx 250 is 165. I would assume they would be some what close in size since they are the same size motor. If in fact it too large that could be the reason why you are getting spooged!

 

[James]

The 330 is a Mikuni jet and the 165 is a Keihin. The 330 is quite a bit smaller than stock and would make sense for the higher elevation and possibly the rad valve. Shady, have you done anything to the needle/pilot/nozzle yet? These bikes run a bit rich on the stock pilot and nozzle at or near sea level so that could be contributing to the spooge at your elevation. How does it run?

 

[shady02]

No I haven't touched the other stuff yet. It runs pretty good just doesn't quite respond to the throttle the way I would like.

 

[James]

The S-8 nozzle and a 30 pilot helped mine a lot. You should get some throttle response improvement with that but you could try dropping the needle before you spend any money and see what that does.

 

[shady02]

What if i just changed my jet from a 330 down to a 320. Do you think that would fix it?

 

[Rider 007]

What if i just changed my jet from a 330 down to a 320. Do you think that would fix it?

No.

Stock MJ on an 02 is a 380 and on an 03 it's a 420. With the JD kit I'm running a 400.

You are waaaay below stock at a 320. I really don't think you can achieve jetting as clean as possible with the Mikuni needles - they just don't have the correct profiles.

You can spend a lot of time (and money) chasing the jetting on that carb or you can shortcut it and pop for the kit or the PWK and get ballpark jetting from others that have made the switch (and it will be much cleaner than the TMX with OEM needles).

Good luck.

:ride:

 

[john stu]

330 sounds lean on the top end......do a plug chop and make sure your plug is not white after wide open throttle.....if its tan start leaning the pilot and needle and then do a plug chop again just to make sure its not lean ....also listen for pinging