200 mxc jetting

Just rebuilt my 03 KTM 200 mxc with some new mods, and I am about to rejet a 2-stroke for my first time so I want to make sure I get this right. Here is what I have been running: 45 pilot, 178 main, NOZE needle 3rd clip. That is with a FMF gnarly pipe and powercore 2 silencer. Premix ratio is 40:1, bike ran good with little to no splooge.

The conditions I ride in: So cal, 0-800 ft elevation, 75-90 deg. F, little humidity.

The mods I did with the rebuild: Engine porting (exhaust port), head polished (no cutting), thinner base gasket (about .75mm to .4), Vforce3 reeds, and wiseco stock size piston. Still have the Gnarly pipe with powercore 2.

Im not sure how these mods will affect jetting. The guy who did my engine work said to go up 2 main jet sizes and get the next richest needle or go down a clip. Sounds right, but I would like to hear what you guys think.

Should i change the pilot jet too or is turning the air screw good enough?

Check the ktm200 jetting forum, you are likely to find someone with the same bike and jetting as yours.

Ok after reading through a few threads, i think my bike needs a 185 main (182 if thats too much), a good needle, and keep the 42 pilot.

I just want to make sure i get it right the first time so i dont have to rejet when im still breaking in the engine.

Is 185 main the best choice??

And I heard about the single taper needles DCJ and DCK working good, so i ordered both of those. are those the best choices besides the JD needle?

I know this info is everywhere on this forum, but please help me out on this.

1. I would start with 185 main.

2. I would also get a single taper needle, ddk was one I remember reading good things about.

3. start with your air mix screw 1.5 turns out

See how you go.

I just took the carb apart for cleaning, and pulled the "air control screw" which is the brass screw below the regular air mix screw, it is smaller and you can see it going into the mouth of the carb. i took it out without counting the number of turns out it was. i looked through the manual and couldnt find out the basic setting of this screw, so what is it supposed to be at...how many turns out??

1.5 turns out from closed. Set it there while you jet, get close, then fine tune with it once you are close.

I have a 03 200 mxc and live / ride in No Ca - temps 50s to 70s now .

Head cut - stock pipe - powercore 2 - 40 : 1

DDK needle 3rd clip

42 - 45 pj

178 mj - was running 182 but ran flat on top - better with 178

~ 1 1/2 air screw

the bike runs very strong with good bottom end and crisp all the way through power range .

It works great in single track ( ride mostly ) to faster HS racing conditions .

the mods you have done dont sound to me like you need to change the jetting. But the jetting you have is not the best for the bike. You are in the right area to move forward with the needles you bought and a 182 or 185 main.

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