200X Jetting

[Glenn]

Last winter, I replaced the stock 108 main with a 110 main. I did this when rebuilding my carb. I can't say I noticed a huge difference. Anyone here ever make a jump to a 112 or 114? The bike is stock, except for a K&N in the stock airbox with the lid still in place.

[250sx]

If your plug looks right then you don't need to change the jetting. More fuel won't help if the engine can't use it. I wouldn't worry about it unless you go with a bigger pipe, cam, or other mods. Have you done a plug chop?

[bones200x]

With the cam and xr200 carb, Mine has a 120 main. I tried several. It came with a 110. It wouldn't rev out to rev. limiter in 5th. it seemed hungry/starving at higher rpm's. So I bought a set 120-130. I tried the 130/ Fell flat-busting out about half throttle. So I went down to 125. Did better. About 3/4 throttle then. then 120. It will rev to rev limiter now. Has more mid range too.
You need to do plug chop's and try different things. I don't know how mine will do in winter. This will be the first winter for it. It ran awesome the last COOL day I rode it. I haven't touched anything since I set it up.

[chrisr200x]

I was alweays under the impression that you only need to rejet after adding a mod like a pipe and stuff like that. If its all stock use the stock jetting.

[bones200x]

Well. When they was stock, they was good. But you can always tweak. Now days, ALL 4 wheelers ARE LEAN. I am thinking trikes did too. I know some of the new dirtbikes come with 2 or 3 different needles for the carb. I know that some of the new Honda Power Up kits come with diferent needles and jets. The power up kit for the CRF 230 comes with new needle and main jet. The only other mods are the spark arrestor and cut out(or take out) restricter in the airbox.
I think you can change jets to make a stock machine more responsive. I tweak everything I own, whether it is a car-truck or bike.

[ZSK]

That 's only true if the stock jetting is correct. Rejetting may be needed if stock isn't right. Best example are a lot of new quad especially the yfz. They come lean from the factory to pass emmissions.

Beat me to it Bones.

[Glenn]

Cool, I was just wondering because my pilot was a bit lean stock. After bumping it up, it started better.

[xd 200x]

what size jet do you think One should go to if they are running a dg exhaust k&n filter and no air box lid?

[bones200x]

what size jet do you think One should go to if they are running a dg exhaust k&n filter and no air box lid?

What size you have now? 108 stock?
I have 10:25 piston, head shaved .020",DG/Cobra exhaust, Uni airfilter.
I would reccomend TRYING a 115-120. You should be able to get like 5 jets in a pack at the dealer. Mine has ranges from 100-120 , 120-130, 130-140. I would stick with Keihin jets. Dynojet numbers aren't the same size.
Remeber, I am talking about 5 DIFFERENT jets in a pack. They do sell 4 jets in a pack for street bikes. They are the same size though.
I am thinking of changing my pilot jet. My fuel screw is over 2 1/2 turns out. I don't know what size I have. I think it is a 38? I will have them see what a xr200 has stock first.

[Glenn]

Maybe I'll try lowering the clip before messing with the main.

[bones200x]

LOWER then needle? Are you trying to lean it out? I would try raising the needle. The worse it would do , is not run out on top end. Oh I forgot to mention, I had to lower my needle one groove on the XR carb. After I installed the 120 main.

[Glenn]

LOL! Lowering the clip that holds the needle should raise the needle. :)

[bones200x]

My fault. You are right. I wasn't thinking when I read it..
If you raise the needle all the way, and it still does ok.....Then you could go up on the jet size. You could leave the needle all the way up. Until it starts busting out/ running rich. When it does that, the needle could be lowered to fix. Never tried that before. I think it should work???????