KTM 250EXC cutting out problem. Help!!!!

About 2 months ago I bought a 2003 KTM250EXC racing with 120 hours on the clock. Done about 10 hours on it since then with no problems. Until yesterday!!!

Left home 8am, bike started on the button and called in to top up with fuel. About 4 litres, Shell Optimax as usual.Got on bike, took about 10seconds of turning over before it would fire-very unusual.

Rode bike for about 2 hours with plenty of stopping and restarting without a problem. Then after a slightly wet lane the bike cut out after about 15 seconds of being on tickover. Took about a minute of turning over to restart and then wouldn't tickover or pull away unless very gentle on the throttle. As soon as I tried to accelerate hard it just cut out again.

This happened another 3 times before I finally got the recovery people out to get home.

Symptoms are Start great from cold first turn, after a few minutes on tickover it cuts out. Then a b*st*rd to restart. When it does restart, if you try and rev hard straight off tickover it cuts out. But if you build up slightly slower, it will rev as normal.

So far today I have-stripped and cleaned carb-nothing wrong. Checked feul cap vent-OK. Checked feul-no water contamination or dirt. Plug-dry black sooty colour. Air filter dirty but not blocked,-cleaned ,oiled and refitted.

Still got the same problem. Any ideas??????HELP!!

Cheers Tony.

Hi I am am having the exact same prob as you with my 250, I'm new here but would be ever so grateful if you have any clue as to how to remedy this prob, my bike is the 250exc racing with the same hours ridden as yours, I seem to think my bike suffer's after a wash or going in water, I've had it set up once with a KTM mechanic and it starts ok and then just won't tick over and cuts out on acceleration as soon as any water goes near it, I am careful not to get water in the carb and plug the exhaust when cleaning, and my filter is clean etc, it's a bugger, I haven't ridden the bike at it's peak yet!

best regards


Spark plug caps are a good place to look. The wire can get pulled out of the cap a bit. Unscrew the cap from the wire, trim a little off the wire and screw the cap back on.

I just read your thread.

I ride a 450exc. Have you made any progress figuring out the problem yet?

i have the same problem with my 04 ktm 250, did you figure out the problem?

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