Oh no! I think my motor died!

Well... It was showing signs of bad.. liek great loss in power. and some other crap. Well. i was riding down the hill, and i herd a noise. It was like.... like a small thud of a sort. But it lost all power. And when i pulled the clucth in to stop, it shut off. Ok. so i kicked it liek 3 times, and there was almost NO compression, like it just fell with like 4 little(LITTLE) slow downs. it happend about 20min ago. i le it cool down a bet and kicked it to see if anything has changed. It will still go down ifi set my foot on it with barly any slowdowns. B4 it would go down stop(1sec) then go down stop (1sec) go down stop, and it was at the bottom. not now, its like dunk dunk dunk, its down.. i have no idea. i dont think it would juet all of a sudden go bad.. but it did.. and it sucks, because i dont have anyting to ride anymore..

II dont know ill take some stuff off after it cools all the way down.

until then.. what do you think?

~~~UPDATE~~~

i took part of the head off, and i saw the top of the piston and the combustian chamber. They were both pretty dirty. crusted with a layer of... black stuff.. , so i think that almost all the compression is gone. so ill probely need a top end rebuild replacement kit (i dont know? what do you want to call it) But im very dissipointed :( :bang:

(lol, the piston is really small)

John Cena said:

Have you actually got the piston out? It sounds like a piston ring broke, might need some cylinder replating.

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no it was getting dark, and my dad would have had a heartattack if he saw me.. so i didnt get that far. ill have to wait for his approval (there os only 6 bolts... not like i would screw it up, and its MY dirtbike, nobod else rides it, and i have to buy EVERYTHING fo it.. so i dont knwo why he wouldent let me) well i really dont want to replate the cylinder because im kinda short on cash.. but.. i can probley get my parents to help pitch in. and from what i saw there wasent really any scratches on the cylinder, but i didnt take it out and look. so when i take it out agian i will take some pics and see if there is any damage.

Badgadjit1 said:

ya definetly...pull that cylinder and check for scarring on the piston and cyclinder...this happened to me exept my wrist pin clip fell out..and my piston was done and my cyclinder was scarred really bad...if the cyl has any scarring have it looked at or take a picture and post it..you may need a replating. or check e-bay for a used cylinder for around 100 bucks, its cheaper, and thats what i did..good luck

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ok. a USED cylinder so that means, there there CAN be like small cant feel them scratches, like those itty bitty ones, but if i can fee the crove, ro it looks bad, then no? i dont know ill put some pictures up and see what you think.

i can get a new pison rings, clips and every thing but the cylinder and connecting rod for $57.00

Thanks for your help, ill take it more apart today or whenever i can and take picures.

dirt bike dave said:

If it was hard and crusted on , just carbon from burned gas and oil.

If there is lots of black powder in there, it could be the remains of a bearing.

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it was encrusted on.. so i dont think it was bearings..

Badgadjit1 said:

if you where ognna get a used one you would want to make sure its not scratched, but like with my yz, its more common to find a cyl used but i'm not sure for you. If need be you might have to go the replating route....thats only if you have a nicksil plate cylinder, if your cylinder isn't replated just have it bored out and get a bigger piston. Boring isn't expensive.

this is who i used on my kx. nice guys, cheapest prices that i could find, and the do good work.
Luke's Racing <- Click it

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$150.00 wow! and if i interpreted it right. is it only $30.00 moe to bore it out? i think thats what it says. and if im wright. then ill probley go with that to get the little extra power out of it!

but thanks for that website! i live about an hour away from there..

Ok. Thanks for the help. I took it all apart, and i did take pics but i cont have my camera with me so ill post them as soon as i get it back. But besides all the crap on the top of the piston there is not major damage. The cylinder walls are fine, no scratches, and the piston looked ok. And my cousine lokoed at it and said it was fin, just get new rings. he said when he put it togeather he got cheap rings just to get it working, because thats all the place had at the time. So thankfully no major Difficulties and it will be fairly cheap to fix. But thanks for the help anyway.