Two-stroke does not start after top-end

Hi,

It's KTM SX 65. I checked fuel, air, and spark plug (sparking).
What else might be wrong here? Power valve?

Thanks,

Compression test would be a good idea, if everything else looks good.

Is the plug wet or dry after you've kicked it over several times? If wet try holding the throttle wide open while kicking. No luck, put in a new plug. If the plug is dry, try putting a little gas in the plug hole then kick it over. Has the muffler been repacked? If it is clogged with carbon, the bike may only run at low speed if you get it started. More obscure would be a sheared flywheel key putting the timing is off. If the ignition coil is failing, the plug might spark out of the motor but not in the motor. Sometimes the high tension lead is not anchored in the plug cap very well. You can unscrew the plug cap from the wire and cut the wire back 8-10mm, then screw the cap back in.

Usually the problems tend to be more fuel related if you have a good strong spark. Some fuel should come out the overflow hose if you lay the bike over. A clogged inline filter can make the bike hard to start and it won't rev out if it does run. Is the gas fresh? It can make a difference; more so if the bike hasn't been run in a while.

Neil; That's expert-level guidance. Well done!

Bruce