New KTM issue

[jesse_54]

Recently I bought a 2010 ktm 250 sx with approx 8 hrs on it. Bike is in great shape and it wasnt ridden hard. I took it out for my 1st ride and it ran good all day until the end of the day, I couldnt kick the bike over. After 5-10 mins of letting it sit it finally started up and was able to make it home worry free. Changed the tranny oil the next day and noticed that the fuel mixture screw on the carb was completely gone! It must have fallen out at some point during the day. I pulled the carb out and tore it apart to clean it and make sure everything was ok. The carb was nice and clean except for the idle jet was plugged with a bit of sand. Cleaned all the jets and re assembled and am waiting on a new fuel mixture screw to be ordered in. Was just wondering if there was any other possible damage done by this or has anyone else ever experienced this? Im hoping that this was why my bike was extremely difficult to turn over and it wasnt something else...

 

[arnego2]

Dirt can cloak a carb pretty easily. But I don't think it was just the pilot screw. I'd think a lean seize maybe?

 

[jesse_54]

So after cleaning the carb and installing a new mixture screw and washers the bike fires up flawlessly. Hope this helps w/ anyone who happens to have the same problem.

 

[salgeek]

If you could not kick it over for a time you seized it. Might be a mild seize. Pulling the jug is the only way to know the extent of the damage.

 

[jesse_54]

When I say "could not kick it over" I mean the bike will not start. Not seized as in the kickstarter doesn't physically move. It does. Sorry my bad on the terminology.

 

[pesky nz]

with the mixture screw missing the jetting vill be bad enough at closed throttle to not run and will probably be lean sucking air in the mixture screw hole instead of drawing petrol into the motor. once over about 1/8 to 1/4 throttle the problem may not be felt. It is possible to have suckedsome dust into the motor through the hole left by the missing mixture screw but probaly a very small amount. If the motor did not lock up at any time then a good carb clean out and a good reed valve clean out should be done. Unless you find lots of dirt I would not strip further than that. You will also be able to see the piston surface and if you can still see machine marks around the piston your good to go

 

[jesse_54]

I don't think that any dust or sand got into the motor. I narrowed it down that the screw fell out on my last 3 miles of riding, in non dusty conditions. Right away I gave the carb a thorough cleaning and there was a small amount if sand in the idle jet. Didn't ride the bike again until a new screw was installed.

Ive put about 4 hours on since then and the bike is running strong. I never checked the condition of the reeds or the piston, do you think those steps are really necessary now seeing the bike hasn't blown up yet?

 

[pesky nz]

Not really necessary no, and with three hours of running whatever entered is most likely eaten up and gone and should not cause any preventable trouble. Happy riding