20 Most Recent 2008 KTM 250 SX - Page 8 Questions & Answers

run a compression check to see if it is low. If low squirt some oil in cylinder and rerun. If it stays low possible valve guide problem. If oil fixes compression then the rings are bad.

KTM Motorcycles | Answered on Sep 08, 2015

A backfire is unburnt fuel igniting. Check you have no air being drawn into the engine through a split in the carb rubbers or a loose carb rubber clamp. The easiest way is to let it idle/tick over and spray some carb cleaner around the rubbers. If the engine stutters or stalls then this is where the leak is. An unsealed collector box will cause this to happen as well so check that your exhaust system is correctly sealed and fitted.

KTM Motorcycles | Answered on Jul 10, 2015

Hi,again so its not hidrolic clutch its a cable so this should be easyer to sort out just follow the advice I gave in your first question.
good luck

KTM Motorcycles | Answered on Apr 20, 2015

There is no fixing a head gasket. Replace it.

KTM Motorcycles | Answered on Mar 12, 2015

That is an annoying problem, huh? Have you properly adjusted the clutch freeplay both at the handlebars and at the clutch arm? If you are still having trouble getting the clutch to let go, you might consider checking to see if the clutch springs are shot, but I doubt this on such a new bike. In fact I'm curious if you have a cable clutch at all, or if you have a special hydraulic setup. Anyway, once you get the clutch operating you can get out of 5th gear by pulling the clutch and rocking the bike back and forth while shifting down. Do this with the engine off.

KTM Motorcycles | Answered on Mar 10, 2015

thats easy take clutch cover off and watch how the plates are on and just copy it excactly the same

KTM Motorcycles | Answered on Feb 24, 2015

sound to me like the clutch slave cylinder. follow the pipework down from the bars to the casing. Unbolt the slave cylinder and im guessing it will be covered in break fluid. new slave cylinder is the answer hope this helps

KTM Motorcycles | Answered on Feb 17, 2015

Check for a good strong spark at the plug itself. If its not there you have a bad coil, loose, broken, corroded wires or bad grounds.

KTM Motorcycles | Answered on Feb 08, 2015

Your model ran the same engine to 1997, then changed to the engine which ran from 98 to now. The 150SX engine bolts straight in too..

KTM Motorcycles | Answered on Jan 31, 2015

has some one messed with the idel screw???

KTM Motorcycles | Answered on Jan 30, 2015

Compression test is read in psi and a leak down test read in % leakage. 20% leakage is not good. with the leak down gauges in place, listen at the carb or end of the exhaust and in the oil fill hole for leaking air. That will tell you if you have a bent valve or broken ring.

KTM Motorcycles | Answered on Jan 23, 2015

check with a squirt of oil down plug hole, then re test see how high it goes then, could be the top ring gone, if this is the case it may need a glaze buster to remove any slight lip that has worn in, or a rebore.

KTM Motorcycles | Answered on Jan 22, 2015

if you smell coolant in the exhaust then the head gasket is most likely blown!
That will definately keep it from idling properly.

KTM Motorcycles | Answered on Nov 25, 2014

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