KDXRIDER.NET

My KDX 220 randomly revs by its self when folding, and runs like poop when riding, except when hitting power band.

Little background of the problem: It would run for 5 mins, back fire, sputter and cut off. I'd take the plug out and wipe it off, start it run 5 mins, back fire, sputter and cut off. Wash, repeat.

I checked everything and finally found some chipped and way out of spec reed valves.

I ordered the boyesen power reeds, exhaust spring, clutch gasket, and clutch lever. I also took the head and cylinder off to check the piston and walls out while I waited for my parts. Gonna need a new top end as soon as I get the extra money. Had some decent little scratches on the exhaust side of the piston. Cylinder looked good, surprisingly.

Anyways, parts arrived and I put everything back together including the new reeds. Also cleaned the carb since it was already off.

It wouldn't start, so I checked for spark, and nothing. Put new plug in and still nothing. Checked all wiring and found I had a bad kill switch. Disconnected it and it has spark.

So, started it up and it revved up really high. Scared the piss outta me, haha. So, knowing I had no kill switch, I frantically grabbed the spark plug and got shocked pretty good as I unplugged it.

Found that the throttle cable was routed poorly , causing it to rev really high. Got that straightened out and now when I start it, it wants to rev up kind of high randomly, unless I pull the choke up, then it's not too bad. I tried to adjust the idle and air screw, and it seems to work for a second, but then revs back up and down.


I'm running premium gas. I was sure how much gas was in the can, so I just added 2 ounces of oil in it. Wasn't much gas.

I know the throttle cable is routed correctly, because the throttle snaps back now, where as before it would slowly roll back.


Any ideas? Sorry about the long post.

And of course I had to take the lip s apart to remove cylinder, etc. If I put that together wrong, could it cause problems as stated above?

Man that RED KDX is fighting you every step of the way.

I would check for air leaks, especially since you pulled the jug and replaced the reeds.

I know, man. It's crazy. I went to put the clutch lever on yesterday, and the perch broke. It's always something, haha. This thing gonna be brand new by the time I get done with it.

And yea, going to the store to get some gas. Gonna start it and spray some carb spray around the intake and see if it revs any.

I got some new gas and mixed it to where I know the ratio is right, and I don't have to random revs anymore. No idea how that would fix it, but whatever. But now it won't idle...at all. And it barely lift the tire off the ground in first when getting on the gas. :/ sigh

Also, no air leaks that I can tell.

Definitely double check your KIPS operation. If it's stuck open, low end power will suffer dramatically.

I think I'm just in over my head with this one. I'm seriously contemplating selling it.

Sorry to hear you are feeling that way. Maybe just put the bike away for a day or two and come back to it with a clear head.

If you decide to sell it, let me know.

You'd be the first I'd let know. I know you could get it running right, haha

I just checked and I have a 160 main jet and 48 pilot. How's that sound? What is yours set at, Ted? I know we live close by.

I have a 155 mj and a 40 pj. I also have a #7 slide. The 155 is just a little rich in the summer and perfect for our winters. I dont ride WOT much so the 155 usually just stays in there.

Edit: Forgot you have a 220.