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ok guys, going down a logging road at WOT in 6th gear and then back tire locks up and i'm doing a 100ft skid on the dirt road. it was at the start of the ride and i thought i had warmed up the bike enough. i swapped the plug roadside and it still would not start after 5 min of kicking it... luckily the road was on a very long uphill and the ride back to the truck was downhill. as i am coasting back down the hill to the truck i try and bumpstart and it fires up but it is a bit boggy ( if thats a word) the engine will rev up but not very fast. lots of spooge out the tailpipe. after the long trip back to the truck with the bike just idling it seemed to clear up. does not appear to be losing coolant, and the engine oil is not milky. i did have an issue with lots of fuel poring out of the bottom of the carb but it seemed to slow down once i was riding. do you guys think the motor may be #*%!'d . just looking on advice on where to start. any help at all would be appreciated. 99' kdx 200 frp milled head (216 kit). like i said before the bike seems ok now and running ok. just he spooge out the tailpipe worries me... thanks!!

Sounds like a piston seizure to me.

it seized. take it apart and use sandpaper to get the pistons aluminum off of the cylinder wall.
look under the piston top (the underside of the piston) to see if oil has been baked onto it and if it is black then your jetting is too lean.
If you have a Wiseco piston you have to let the bike warm up longer because they are prone to startup seizures.
after reassembly check your compression. If it is low then probably you're having run the engine after the seizure wore grooves in the piston rings (from the aluminum on the cylinder) and so you have to replace them.

hey thanks for the reply Jaguar, do you think something could have plugged the main jet ( dirty carb) and starved the engine? i guess ill find out when the cleanout begins... the thing that gets me is that it was running perfect in the few pit rides i had it on in the first few weeks of me owning it. ( i got the bike at the end of jan/15) this was the first time i actually had it going fast enough to get to 6th gear. thanks again

Doubtful that a plugged main would have done it, it would not have run right on the top end if that were the case. As mentioned by others sounds like a seize.

My son has an 05 200. What is the proper warm-up time that you all recommend for theses bikes? I make him chillax (his word not mine) for a few minutes after we get it started. A few minutes feels like an eternity to a 15 year old.
Thanks

I let mine warm up a couple minutes, or start up and ride slowly away. To be honest, both my kdx powered bikes won't even get to powerband if not warm. They just chop up and run like garbage.

You can put-put around till the engine truly warms up, or wait till you can feel cylinder heat through your glove. But even then you shouldn't give it full throttle right away.
yes, trash in the float bowl could of caused a partial restriction to fuel flow in the main jet. When you take it apart use wire from a bread twist -tie (with the plastic scraped off) to clean out the main jet.
read this: http://www.klemmvintage.com/airleaks.htm

Better idea is to use compressed air to blow out the jets. Never a good idea to use wire, especially on the small PJs.

Right on guys, thanks for the help! ill post some pics when i take it all apart and let you know what i find...... im sure hoping to find a bunch of crap in the carb...

ok so i have a couple of pics but cannot post them. the carb was full if grit and chunks. how do i post a pic or two??

I had the same thing happen on a bike I bought to flip. I did a top speed pull and got the same result. Air filter had come apart in tiny little pieces. Bought a new filter, cleaned carb and reed cage, good to go. Sold it to a friend after I put 10hrs on it, still rockin out.

Of worthy mention is to pull the reed cage and inspect. There were large chunks of foam in there. I doubt it would really hurt the engine, but it can't be good.

BURNZ wrote:ok so i have a couple of pics but cannot post them. the carb was full if grit and chunks. how do i post a pic or two??

What kind of grit and chunks?

Find another site to host your photos (like photobucket; I use smugmug). Then copy the pic URL and past it using the URL button I see above when creating a new post.