Hi i have a ktm 250 07 excf which seems to stall alot when warm bike starts first time when cold i have replaced the plug so far can you help

Yes I to have washed a bike to death.You will need to dry the air filter .Is you bike fuel injected?If so take a hair dryer and warm all the connections concearning spark and fuel injection .You should then put dielecric grease on all your connectors.If you bike is carb model then just drain the float bowl.

to me this seems a case of many things not 100% set up properly.

big singles do burn a lot of oil, so either its low or just the wrong viscosity, check with a KTM forum as a lot of users will have already had this problem and rectified it.


but the first thing i'd check first is: Idle speed (if its FI then shouldnt be a problem) valve clearances and it also depends on whether you have any mods?



a race spec pipe will always cause issues starting cold.

Hope you have kept notes on all the carb setting changes.
Did the problem start when the exhaust was modified? If not it may not be a carb problem.
Does the problem change if the engine is cold or hot?
Does it make any difference with the choke on?
Is the air filter new and clean, new plug, valve clearances adjusted, new oil.
I know I havent answered the question, but hopfully gives you a few more things to check

you would be best directed to ebay, type in on your search engine page ktm 250 excf 2007 workshop manual ebay, this should flag all items related to this on ebay. happy shopping.

Do not twist the throttle when re-starting a hot engine. That bike floods easily. The power valve in the carb squirts gas into the cylinder with every twist of the throttle. A fresh spark plug will also help.

Check the fuel filter in the tank, (above and connected to the fuel tap). It may well be blocked.
Hope that helps.

sounds rich, especially if its a problem when it warms up, was the JD kit a much bigger main jet,might need to try standard main, is it standard exhaust, I assume the air cleaner is clean and good condition, the foam can deteriate over time.Not sure if you have a hot start button or lever, this leans the mixture, if you have one and it helps then its definately rich

as a non related hint I use moreys upper cylnder lube in my WR it starts easier, idles easier, doesnt stall as easy under hard braking, and doesnt seem to get as hot and ping when working hard in tight bush.

If you are saying the bike will start fine when cold, but after it is warm it will not start then I would recommend inspecting and or replacing the intake gasket / material. What may be happening is after the bike gets hot the 'seal' is lost and that makes for a lean condition, hence not starting. you may have other issues, however this is a cheap potential solution. Hope this helps,

JP

This is obviously a problem in design of the bike. Weak circuit board design creating a shallow spark or mis-timed spark, OHC timing far too radical, carb design not compatible with the bore of the bike, factory valve angles out of whack, something, or several somethings have converged in this bike. Does your state have a "Lemon Law"? Many states have this and it forces the dealer to refund your money or replace the bike. Contact the KTM Corporate office > > KTM-Sportmotorcycle AG
Stallhofnerstraße 3, A-5230 Mattighofen
Tel. +43 7742/6000-0, Fax. +43 7742/6000-0