KDX200 hard to start/not running

[CarsonMcI]

what do you guys think about me trying a leak down test? I feel like even with low compression it would be able to at least drive around instead of bogging in gear and not idling, plus the adjustments on the carburetor not making a difference make me believe it could be something to do with a seal leaking.

[KDXGarage]

Did it come with an air filter?

Is that piston as scratched up as it looks to me on the cell phone video??

[CarsonMcI]

Did it come with an air filter?

Is that piston as scratched up as it looks to me on the cell phone video??

Yeah the air filter looks really clean though, and yes the video does do it justice unfortunately

[kdxsully]

I'e do my best to rule everything else out before splitting cases. That resource KDXGarage posted looks valuable.

[John_S]

what do you guys think about me trying a leak down test? I feel like even with low compression it would be able to at least drive around instead of bogging in gear and not idling, plus the adjustments on the carburetor not making a difference make me believe it could be something to do with a seal leaking.

I think you should do a leakdown test before tearing the top end down to see if there are currently any problems related to the top end and hopefully not find any bottom end leaks, but at least you'll know. At 100psi plus the piston looking like it does, it's time for a new top end. If the cylinder isn't gouged you can clean it up with a green scotch brite pad and put in your new piston, rings, bearing, clean the power valve, and put it back together. Before the pipe and carb go back on make sure it passes a leak down test. I feel like trying to get it running right in its current state would be a waste of your time. I've done that when I didn't feel like tearing it down, then when I did the rebuild all I could think was "why didn't I start with this?"

[KDXGarage]

Why would you split the cases??

Do indeed do a leak down or vacuum test before top end disassembly.

If the piston looks bad, then it needs to be replaced.

[kdxsully]

Why would you split the cases??

Do indeed do a leak down or vacuum test before top end disassembly.

If the piston looks bad, then it needs to be replaced.

I was probably of a completely different thread, haha. Whoops

[doakley]

I suspect you are looking at a top end rebuild at a minimum. Excellent advice to do the leak down test before tearing apart the top.

[CarsonMcI]

Well guys, I think I found my problem... I think I'm still going to do a leak down test tomorrow just to make sure nothing else is wrong

[rungrandpa]

Ouch. At least you'll have a rebuilt bike when you're done.

[doakley]

Yup, you found your problem. I would not attempt to crank it again. That's nasty!

[Molly's 70]

Yup, that'll do it.

[KDXGarage]

Congratulations on finding what appears to be the cause.

Sorry that it did not turn out tot have a recent or new top end.

"so it supposedly had a new top end when I bought it and you can tell from the new gaskets poking out from the sides."

We can give you some pointers on working on it. My first tip is usually buy a service manual.

[GOT WOODS?]

FWIW, I've developed a cold cranking method that appears to work well for my 220. Open fuel valve for 2-3 sec, close. Open choke, open throttle about half then release back to closed position. Then and ONLY then, kick it quickly in succession. Usually fires on kicks 2-4. Turn the gas back on and after 10 sec or so +/- depending on outside temp, push the choke back down. Thirdgenxli beats me with a stick if I rev the bike while it is cold so I just let it sit and happily idle away while I get ready. ;) After this, the bike cranks on 1 or maybe even 1/2 kick. I've had a lot of cold cranking problems and this system seems to work for my bike. YMMV

Holy cow!!!

Me:
1) <pulls bike out of storage> Put in fresh gas
2) open petcock
3) look at my messy garage and make mental notes while float bowl fills
4) pull up choke
5) kick once, regret not having boots on while flip flop hits against peg
6) kick again, WTF!!!!! IT DIDN'T START!!! MICE ATE MY WIRES!!!!! A MASS CORONAL EJECTION FRIED MY ELECTRONICS!!!!! GOD HATES MEEEEE!!!!!
7) kick a third time, BRINGAGAGAGAGAGAGAGA!!!!!!! <goes for a nice ride>

Just sayin'.....

[doakley]

Yeah. Like I said, I've had a lot of cold start issues with this bike and haven't been able to figure them out completely. Swapped to a buddy's carb and the problem went away immediately so convinced it's in the carb. Saving up my stamps for either an RB or Lectron. But for now, it seems to be working.

[CarsonMcI]

For those of you that like carnage pics haha ->
The good news is that the engine held pressure and that there's no up and down play on the connecting rod. Thank you guys for the replies and suggestions!

[CarsonMcI]

oh does anyone have an idea as to what might've caused this? it almost looks like the rings butted together but I'm not too sure.

[doakley]

Looks like some serious overheating and seizing. Cyl looks like it will be making a trip to Millenium for repair and recoating. I’d be concerned about pieces in the lower end also. Really sorry for you but in the end you’ll have a brand new engine!

[kdxsully]

Wow!! Did you test for side to side play in the rod? Some is okay but there is a service limit. This looks like overheating damage from a lean condition maybe?

[CarsonMcI]

Wow!! Did you test for side to side play in the rod? Some is okay but there is a service limit. This looks like overheating damage from a lean condition maybe?

Yeah, there was some side to side nothing that made me concerned though. It wouldn't hurt to measure it I guess lol