Strange Seizure - 00 CR250R

[Fookle]

Hey guys,

 

I bought the bike early this summer, rode it for a weekend then the top end blew. Put on a brand new OEM cylinder as well as a Pro-x piston, rings etc. Brand new top end. The other day I was playing with the jetting, starting and stopping the bike a few times and playing with the air screw, the bike was fully warmed. Probably the fifth or sixth time I started it up it abruptly killed after a couple seconds, and the kickstarter wouldn't budge!

Oh **** I thought, so I took of the flywheel cover and I could still move the flywheel around, it would just seize at two points. The strange thing is it isn't a "hard" seizure, to where I can't move it past the point, its almost "squishy" at that point but obviously not right. It feels as though if I put enough force on it, or put a wrench on the flywheel nut I could move it......

 

Strange I thought, so today I took off the top end and all looks good, cylinder looks brand new and piston etc looks fine. There are about 8-10 hours on these parts so I expected this. Rod bearing feels fine, no vertical play. ALSO the flywheel side crank bearing has no play in it, I can't move the flywheel around at all. The bottom end has been replaced (previous owner) with a Wiseco brand crank and rod.

 

I'm confused as to what would cause this type of seizure, its gotta be either the clutch side crank bearing or something in the clutch? Could something break free inside the clutch cover and cause this type of seizure? Any help or advice would be greatly appreciated, and sorry for the novel just wanted to get all info up!

Thanks!

Edited August 18, 2014 by Fookle

[LoonRider]

Could be bad crank bearings. If everything else looks good that's what I would bet.

[Fookle]

That's my hunch too. Would my next step be to take off the right side clutch cover, and check things out? Make sure nothing is obviously out of place? I've never played with a clutch on a bike before, but I've got a manual so I'm sure I can figure it out.

[LoonRider]

You can try but unfortunately you're most likely going to have to split the case if you want to replace the bad bearing/s

[Socket]

Wiseco crank. There's your issue.

[Jeremy Finley]

I have had main rod bearings wiseco cranks seize, without having any up and down play in the rod bearing. I would suspect that you will be spilling the cases. Then when you rebuild put OEM crank and never worry about it again!

[TheBoonDocker]

Ditto. Never touch a wiseco crank. Don't know where they build them. Don't know why they build them. Ive read multiple posts of cranks lasting less than 2 hours. Hotrods never did me wrong.

[Fookle]

Sorry for the late reply guys, But I got the problem sorted out! Turns out it wasn't the crank bearings but something else entirely... I just happened to have the rear tire off replacing wheel bearings so the chain was hanging loose on the front sprocket. Well when I started the bike (the last time, when I thought it seized) I must have just barely touched the shift lever and shifted into first, this caused the chain to get a small kink in it behind the front sprocket cover, so I wasn't able to see it. The chain was lodged in there against the case, basically making it feel like the whole bike was locked up! I even tried pulling the clutch in, and it didn't do anything! So I finally found it and straightened out the chain and all is well, crankshaft spins freely when in neutral! Guess that's what you get when you try to work on your bike after having a few brews ?

 

Anyways thanks for all the help, and if I ever do have to do a bottom end I'll remember to avoid Wiseco! ?