MY Friend needs help

[RedEx XCRider]

i have a Friend at school that has an 87 250X he keeps craking his case right around the sproket..does anyone know why it keeps craking? TIA

[nakomis0]

Sounds kinda weird to me...

Does the chain ever 'pop' off?

I'm gonna say, bent ...sprockets, axle hub, or axle.?

Sounds like something would have to hit it to make it crack, and the only thing around there is the chain...

[RedEx XCRider]

yeah he said his chain pops off.

[250rider]

its bc he doesnt have the case saver on, the chain pops off and whacks it reeally hard, i did this when i snapped my chain in half on my 250x.

[sprtrx300ex]

tighten the chain and buy a case saver

[nakomis0]

Case savers are great, but the chain is popping off because of something.

Do this dude... raise the rear und of the bike with a jack, bucket or something. Put it in gear and let the rear tires spin in the air. Look for something bent.. your gonna find something bent.

And if something aint bent, its coming off cause the chains getting loose. Which then the problem more than likely is a wasted bearing carrier that won't hold chain tension.

[TCracin440ex]

ive had the same problem with the 250x chain popping off...but mine never broke the case....BUT i kno the solution...for 1...its your chain/sprockets...ditch the chain, buy a 520 O-ring chain, and some sunstar sprockets...these things occur when your chain and sprockets wear out...the chain stretches, and it curls the teeth of the sprocket there for messing up the sprocket so the chain wont fit proper even if you buy a new chain...my suggestion would be to get chain/sprockets all at the same time, and also make sure the bearings aint shot, lift the rearend up, and see if the axle has any up and down play in it....if it still happens then what possibly could have happened is the sprockets aint aligned and its slinging the chain off...so what has possibly happend is the axle has either slid over to the left a lil bit...or the swing arm bushings cold be gone causing the whole rearend to move....

[RedEx XCRider]

he said his chain pops off mostly when going up hill and he does have a case saver

[RedEx XCRider]

he said his chain pops off mostly when going up hill and he does have a case saver....he said his rear sproket looks like its getiting old...like teeth grinding off would that be the problem?

[ReconRider25]

yes.;) bearings are prob shot too. sounds like he dosent maintain it. what shape is the rest of the quad in?

[TCracin440ex]

yes sprocket tooth decay is the problem...but replace the chain along with the sprocket

[RedEx XCRider]

the rest of the bike is in Decent shape...it looks good to be a 87 but its not Perfect O_O he doens't maintain it to well....Thanks for all the help guys