KTM 250SX carb/jetting settings

[bigboss_an]

Hello all,

I had this post in general repair because I didn't know of this section in the forums. :bang:

A friend of mine just got a 2001 KTM 250SX. Of course I'm the one who has to fix this 'gem' up. Right now this bike would make any steamship on the mississippi proud considering the enormous smokescreen it leaves behind (may come in handy on raceday though). What I need is information on standard jetting and standard spark plugs. I'll start from there and work my way up. I'll probably replace the premix. What's a good starting point for this bike 32 or 40:1? My friend says that he constantly has to replace (or at least, clean) spark plugs to keep it running. I'm hoping that correct jetting and premix will alleviate this issue. Also, I haven't had a chance to take a look at it but the bike apparently has a severe oil leak somewhere from the top of the engine. Anyone had the same happen, any ideas? This weekend I'll pick up the bike, degrease the whole thing and pressure wash it to see where the leak is from, but it is pretty bad.
To make a long story a bit shorter: who has info on standard jetting, plugs, and carb settings for this bike? Unfortunately I don't have the owners manual. Thanks.

 

[husabutt]

Hello all,

I had this post in general repair because I didn't know of this section in the forums. :bang:

A friend of mine just got a 2001 KTM 250SX. Of course I'm the one who has to fix this 'gem' up. Right now this bike would make any steamship on the mississippi proud considering the enormous smokescreen it leaves behind (may come in handy on raceday though). What I need is information on standard jetting and standard spark plugs. I'll start from there and work my way up. I'll probably replace the premix. What's a good starting point for this bike 32 or 40:1? My friend says that he constantly has to replace (or at least, clean) spark plugs to keep it running. I'm hoping that correct jetting and premix will alleviate this issue. Also, I haven't had a chance to take a look at it but the bike apparently has a severe oil leak somewhere from the top of the engine. Anyone had the same happen, any ideas? This weekend I'll pick up the bike, degrease the whole thing and pressure wash it to see where the leak is from, but it is pretty bad.
To make a long story a bit shorter: who has info on standard jetting, plugs, and carb settings for this bike? Unfortunately I don't have the owners manual. Thanks.

There are 7 Jet needles listed for your model. Start with the next leanest needle and begin the jetting process. I think th next leanest needle is NOZH but I am not positive. Check with a good parts person. As the needle controls 1/4 to 3/4 throttle once you get that sorted the main and pilot are easy.

 

[bigboss_an]

Thanks Husabutt,

Over the weekend a good washdown already resulted in a much better looking bike. The oil flowing from the engine turned out to be waaaaayy too much oil in the tranny. Fixed leaky exhaust, oil level screw leak fixed, rear tire remounted (not wobbly anymore), relubed chain etc etc. Anyway, i'll get to the jetting next week. Thanks for the info.