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1997 xr400 Lower End Bearing Noise

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I recently bought a 1997 xr400. Runs great but it has a worn bearing noise in

the lower end. Has anyone had this problem before.

Crank Bearing

Counter balance bearing

output shaft bearing

any help would be great!

My plan was to take both covers off the side of me motor and inspect what bearing i could see (crank and output shaft)

What a jump from my 1998 XR250 280 big bore to the 400!!!!!!!

The XR280 is for sale if anyone is interested. Runs great Street title. $1300

Clio Michigan

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Before you go tearing it down, make sure the cam chain tensioner is functioning properly, and that the torsion spring inside it isn't broken.

If it's ok, make sure the cam chain itself isn't so worn/stretched that the tensioner can no longer compensate.

When the cam chain is allowed to run with extreme slack from either cause, it makes a growling noise, very similar to crank bearings.

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I thought about that but was told it makes more of a slapping noise. I will definatly check it out though. Much easier to look at that than lower bearings.

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I removed the cam chain tensioner, inspected it, reset it, and reinstalled. Everything seemed to be correct. Noise did not change one bit. Should I be worried about this or should I ride it untill I have to do somthing?

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If it was me i would take the left hand statter cass off first, and check for play at the flyweel to see if its the mains. is there much vibes? and dose it smove out a little under sum light load?

Edited by Hardergamer

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Well my dads 99 xr needed a clutch so we took both xrs apart at the same time so I could compare. I started by taking the flywheel side off and did not find any play in there. Tried to take the fly wheel off but could not get the bolt out and did not have a puller so I put it back together and moved to the other side.

I removed the covers from the right side of the motor and there was water in the oil under the small clutch cover. Turns out the clutch shaft is leaking. I moved on and removed the clutch and basket. This is where I have some questions.

Does the shaft that the clutch attaches to turn all the time or only when the clutch is out?

When I took all the clutch parts out the saft makes way more noise than my dads. Its noisey but smooth. I would say this is the problem if it turns all the time.

Did not see anything amiss with the crank bearing on the right side and the all the cam chain stuff was nice and tight. The only things I did not see are the counter balance bearings, left side crank bearing and the connecting rod bearing, as far as I know.........

Sugestions please!!!!

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Download this free shop manual. http://www.sendspace.com/file/ivcn6l

>>>>>>>I removed the covers from the right side of the motor and there was water in the oil under the small clutch cover. Turns out the clutch shaft is leaking.<<<<<

Are you talking about the clutch arm, the lever that the cable connects too? That seal can be replaced.

>>>>>>Does the shaft that the clutch attaches to turn all the time or only when the clutch is out?<<<<<<<

I assume you're talking about the clutch main shaft that both the clutch center and outer mount on? Yes, it spins all the time.

Can you tell if the bearing on the shaft shows any signs of rust or galling? You say it's smooth, so no ratchety/notchy feeling to it when you turn the shaft? Any in/out, up/down play?

Sorry can't be of any more help. Hard to diagnose over the internet.

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