KTM 250 1980 Mikuni Jet Set?

[Husabergpete]

Hi There KTM Chaps,

Does anyone have some rough settings for running a 36mm Mikuni on a 1980 250GS. Guro Goold is about to breath life back into the old girl and a starting point for the Mikuni would save me some grief.

Many thanks Pete

[Husabergpete]

For future reference -

Used a 36mm Mikuni off a working  1973 Husky WR250. Worked fine to start and run. Might need fine tuning but here were the specs when it went in.

Slide - 2.5
Main Jet - 380
Needle - 6DH2
Pilot Jet - 40
Needle Jet - 159 Q-2

Darryl Lewis suggests -

Maint Jet - 290
Pilot Jet - 45 - 50
Needle - 6DH7  or 6FJ6

[oz555ktm]

I am a Bing Man

I would go with Darryl  because Brad Lewis  would know 110%

[Tahitian_Red]

For future reference -

Used a 36mm Mikuni off a working  1973 Husky WR250. Worked fine to start and run. Might need fine tuning but here were the specs when it went in.

Slide - 2.5
Main Jet - 380
Needle - 6DH2
Pilot Jet - 40

Darryl Lewis suggests -

Maint Jet - 290
Pilot Jet - 45 - 50
Needle - 6DH7  or 6FJ6

HusabergPete,

Are those numbers correct?  You run 9 main jet sizes bigger (in the same 36mm Mikuni) than Darryl?

[Lozza]

Needle is different, net effect would be the fuel annulus is probably the same

[Lewo81]

Hey guys, I noticed the big difference in main jet size also. The numbers are only a guide to start. Trial and error is the only way to end up with the correct jetting specs. Interesting to see what the final numbers will be.

[Husabergpete]

Gents,

Yes the Main is currently that much bigger than suggested. But it was a carb given to me off a working Husky 250 so I thougth I'd start somewhere. The bike has really only been run up and down the street at the moment. It starts really well, Idles well, revs freely but when it's riden in the higher reves it runs poor. Intend getting the clutch to disengage fully, give it a bit of a run around a paddock and most likely move closer to the Mr Lewis' settings. Will keep you posted. By the way the clutch issue has more to do with the aftermarket clutch pull housing than the clutch itself..

All the best

Pete

PS As of 11/3/09 - Only changed the main from a 380 to a 290 and left the needle, pilot, slide and needle jet the same. Did try a 6Dh7 but didn't help. Running not bad.