I picked up a 2002 KX65 for my son. I finally got it all dialed and running, took it for a test run and the throttle seemed to almost want to stick and runaway on me. It's adjusted properly, the throttle twists just fine at all extreme angles of the handlbars, so my question now is with the routing of the cable.
Right now it comes from the handlebars, across the front of the head tube and between the top of the radiator and frame on the left side. It continues beneath the gas tank along the left side(sort of underneath) of the frame and right there is a seeminly tight turn into the carb.

Is that route correct? Last thing I'll need is a runaway bike beneath my 8 year old son on his birthday. I have 3 weeks before B-day so I need to get this last bit dialed and I'm all set.

The throttle tube is probably to far in and the end of the throttle tube is rubbing the bar end. I have router the throttle cables several ways and they all worked, but yes your routing is fine but I find I have more cable room running the cable on the right side of the frame not across the head tube and by the radiator like you describe.

Try this, take the throttle off the bar and see if it turns without being on the bar. 9 out of 10 times that is the issue. I have even had to grind Renthal bars down as the throttle tube fit too snugly after cutting 1 inch off the end of Renthal Mini bike bars.

Your cable is routed correctly.
If someone bent the cable at any time it can pinch it permanently and cause a binding effect at a certain amount of twist.
Sometimes, your cable cover (the black plastic) will break or wear through (could be at the throttle end under the cover), if the cable catches something or is is tight at one extreme end of movement or someone pulls too hard on it to get the throttle with cable attached over the bar end, it can stretch the metal wound cable shield under the plastic outer shield and this in turn will lengthen the outer sheath, in turn making the cable tighter/shorter as an outcome, this will get the cable pulling up on the slide - seen this before but it took quite a bit of investigation to determine this being the problem. At that point - you need to replace the cable.
Also - as already stated above - disassemble the throttle - dirt can easily make it stick. Remove the cable and spay cleaner followed by fogging oil through the cable to clean it out internally and lube it again and make sure it has smooth travel end to end.

Do not oil or grease the throttle tube. Lube the cable sheath and cable. Put the tube on the bar bone dry. I see guys try and lube it, or worse grease it, all that does it casue it to stick.

The problem definately is not the throttle tube on the bar. That movement works perfectly.
matt4x4 describes my problems exactly. Perhaps the throttle cable got kinked at one time... The sticking is pretty minor, but might be enough to frazzle my son.

Thanks guys!

if you feel it's the cable, remove it, inspect it, if everything is good visually - then just try and straighten it out gently, feel for any flat spots that could cause friction and get it moving freely, reinstall it and test - or for 15 bucks, you can probably buy a new one.

Route the cable around the frame head of a KTM 65 :smirk:

Why??? So you can repair everything else while you're at it???:banana::banana::banana::banana: