what it may be

[bad96z71]

OK guys, just bought a 92 kdx250, now when i bought it it was locked up i was told they was riding a trail and i guess it locked up , when moved it again it broke free , ok when i talked to the guy he said they kicked it over twice and it locked up again, when i went to look at it it was free, i kicked it over about 4 times and there it was locked up again,,,now i pulled the head off just to see the piston and from what i can see the piston looks fine and what little bit of the cylinder looks to be ok, it got dark on me so ccouldn't go any further but if ya try to kick it the kick atarter will go down but with great force and the motor will not turn over , aside from the worst part being the crank, is there any gears that may be behind that cover that can cause this maybe, i don't know anything about these motors is it possible that maybe the piston can hit the power valve assembly any help would be great sorry if this is all confusing thanks for your help

 

[mideastrider]

Could be a # of things. But I would go ahead and pull the cylinder off and check for any damage there maybe a skirt broke off the bottom of the piston but if that were the case you should be hearing weird noise's when it does turn over. If nothing there pull the clutch cover look for any damage. Pull the clutch basket to disconect any thing from the crank and see if the crank will turn easily by hand. By now you should be able to tell if the problem is in the bottom end or in the transmission. Just a thought hope it helps.

 

[bad96z71]

hey thanks alot for the info, i now know what it is the bearing are toast on the crank so now its time to split the cases and see how much this will cost me

 

[bad96z71]

well need some ideas on how to get the kicker off i cant seem to get a gear puller to stay hooked so any ideas this thing is on there

 

[QKENUF4U]

just went thru this exact problem with a customers bike.
pull the engine out and start your tear down. more than likely its a bad bottom rod bearing. so its time for complete rebuild.
as for your kickstarter, take the bolt OUT and just start wiggling it back and forth. if you can hit it with some PB BLASTER and let it soak for a few minutes. while its saoking hit it with a hammer around the kick start shaft to loosen it up a bit. it should come off by hand and a bit of persuasion.
but like mideastrider said, start by removing the clutch basket etc. to seperate the trans from the crank, that way you can narrow it down to one part of the engine. CRANK or TRANS. (just make sure the bike is in nuetral when checking the trans) you can use the bolt on the end of the crank to turn over the crank and see if it locks up on ya.
oh my customer used a COMPLETE crank kit from HOT RODS. it was 360$ for the complete kit which to me seemed like a really good deal. just had to have my machinist check the cylinder for any problems then reassemble the engine. if you dont have the ability then just take the engine to a dealer and have them go thru it for ya.
good luck
good luck

 

[bad96z71]

got the kicker off had to put just a little heat on not much , finally got the gear puller to hook so thats done , yea its for sure the rod bearing you can just move iton the crank and feel it trying to seize , but now i just need to get a flywheel puller to complete the task and dig in thanks for all the info guys

 

[jason33]

you shouldn't have needed heat and a gear puller!

 

[bad96z71]

you wouldnt think so but thing was NASTYYYY in those splines its all good now it runs and runs good