crf250x bottom end jammed

last weekend i was riding down a gravel road and all of a sudden my bike locked up so i thought the timing chain piled up or it just seized so i checked the piston and timing chain they were both good so i took the flywheel cover off and took out the flywheel and seen there was a bunch of bronze peices in the oil screen looked like peices of a washer or something i took a wrench and can turn it backwards and then forward again but only to a certain point then it jams up. anyone know what this is?

if i knew how to post pics on here i would show you

Crank big end bearing is trashed. Gotta split the cases and replace the crank. Get the cylinder and piston off and you will see that the roller bearing is destroyed. The bronze pieces are from the thrust washers.

okay so i cant just replace the bearings i need a whole crank?

New crank or crank rebuilt with new rod and bearings. The big end bearing needs to be installed when the crank is pressed together not something you install separately.

At oil changes inspect the outer pleats of the filter carefully, even if you don't change it. The 1st sign of bronze colored metal debri don't ride again, it's crank time.

is the 05r crank the same as the x?


Just get a crank from Hot Rods or get a rod kit and have a local machine shop press it. I would go with the Hot Rods kit, have used them before and the quality is awesome.

Breaking the bottom end apart is a somewhat detailed job that takes some special tools and knowledge. If you aren't comfortable with it or don't want to buy the tools, ask around your local track for a reputable mechanic.

okay i will. but whats the difference between the x crank and the r crank?

One of the ends is different.... Can't remember off the top of my head whether it's the stator side or clutch side.

Whatever you do, dont hack it together. Be sure to initiate a full rebuild (aside from head). You will only get as much out of the bike as you put into the bike.

just do it right and have someone else rebuild the crank or get a new one, you dont want to have the engine back apart in a few weeks because you wanted to save a few dollars

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