2001 kx250

[rooster300ex]

I just go me a kx250 and the bottom end sounds like its grinding, when I drained the oil it was gray. not watery what do ya'll think it is i think its the crank bearings.

[usp4u]

does it get better or worse when the clutch is pulled in ?

[KXRida]

By grinding you mean? Where is it coming from? What makes it worse/better? Does it do it when it's moving/stopped/both?

Bad crank bearings tend to make more of a "knock" sound than a grind sound. A grind is usually due to two pieces hitting (i.e, usually not a bearing) so it could possibly be a clutch/drivetrain issue. Was there any metal in the oil that you happened to see? Did you pull the clutch cover off at all?

The more information, the better

[rooster300ex]

Originally posted by KXRida
By grinding you mean? Where is it coming from? What makes it worse/better? Does it do it when it's moving/stopped/both?

Bad crank bearings tend to make more of a "knock" sound than a grind sound. A grind is usually due to two pieces hitting (i.e, usually not a bearing) so it could possibly be a clutch/drivetrain issue. Was there any metal in the oil that you happened to see? Did you pull the clutch cover off at all?

The more information, the better

The sound is coming from the bottomend. When you rev it it gets louder. Now it will no longer start even with a brand new plug. I don't think there was any metal in it, but I didn't look real real close. Same if you pull the clutch in.

If you pull the clutch cover could I possibly be able to see whats wrong?

[KXRida]

Pulling the clutch cover and giving it a once over would be a start.

[John451]

So when you were asking about if it made the noise when the clutch was pulled in out let out what would it be if it made it louder with the clutch out? Because on my rm250 makes this kinda cool sounding knocking noise when i let the clutch out, it shakes the motor, frame, handle bars, it shakes the whole bike. I always thought that it was because someone got a bigger piston in it and it was not balanced. Could it be the crank bearings? It's been like this for over a year now.

[usp4u]

John, good god man. I've never heard an engine knocking in a manner that I'd call "cool sounding"..Ask you self this...If it were the piston/crank balance issue why would clutch engagement effect it?" It wouldn't. Pull the clutch cover, both of you guys. It would be smart to just pull that whole side outer case and see if you've something going on in there. Theres several small gears that have to run off of each other and mesh nicely.
Then pull the igition cover and check for up/down play by grabbing the stator and lifting. This can help identify crank bearing issues.

[John451]

Originally posted by usp4u
John, good god man. I've never heard an engine knocking in a manner that I'd call "cool sounding"..Ask you self this...If it were the piston/crank balance issue why would clutch engagement effect it?" It wouldn't. Pull the clutch cover, both of you guys. It would be smart to just pull that whole side outer case and see if you've something going on in there. Theres several small gears that have to run off of each other and mesh nicely.
Then pull the igition cover and check for up/down play by grabbing the stator and lifting. This can help identify crank bearing issues.

Hahaha, it's more of an abrupt purr. Or a purr of knocking? The bike runs like no other of its age so i'm not too worried which is why it sounds cool. I just had the whole clutch out and apart to check out the clutch plated because I had to take the clutch cover off because there was a hole in the cover that the last owner glued together so i replaced that and I have to replace the inner gasket later so is there anything i should look for while I'm in there? But the noise is wierd. It only makes it when its in neutral with the clutch out, it doesnt make it while its running. And it's not a gross clanking knock so whateever's moving is not moving very much.

[KXRida]

Originally posted by John451
So when you were asking about if it made the noise when the clutch was pulled in out let out what would it be if it made it louder with the clutch out? Because on my rm250 makes this kinda cool sounding knocking noise when i let the clutch out, it shakes the motor, frame, handle bars, it shakes the whole bike. I always thought that it was because someone got a bigger piston in it and it was not balanced. Could it be the crank bearings? It's been like this for over a year now.

Welcome to the world of rm clutches. If it's doing it when the clutch engages/disengages, it's most likely a clutch issue. Why does everyone think their crank bearings are suddenly failing? :confused:

The first thing I did with all of my rm's was a hinson basket and barnett plates.

Taking the clutch plates out is only the beginning of the clutch. Could be a loose hub, bad pressure plate, etc. There's no secret that rm clutches are garbage. Always have been since roughly 88' and up.

[usp4u]

i wouldnt call RM clutches garbage. But, a Hinson basket is a wise move on any bike. I beat the everloving snot out of an 02 125 and 04 250f for 3 years each with no trouble.
John, if I were you I would have the entire clutch assy. out on the floor and be snooping around all the driven gears behind the outer case cover. I would also be taking a hard look the disengaing mechanism...the pushrod, basket,inner hub,pressure plate, AND dont forget to inspect the thrust bearing that rides on the inside center of the pressure plate. You could have something as simple as a loose basket/inner hub. Check the basket fingers for grooving from the fiber plate tabs. Check the inner hub for damage from the steel plate "cogs".

[John451]

Thanks, I was mainly lookin to see if anyone had this problem before to save me some tinker time. I've been workin on bikes for 8 years and been a dirtbike mechanic for 4. The reason why I looked at the clutch plates was out of curiosity I wasn't tryin to loook into the noise I just wanted to check for wear because I want a barnett clutch. But it just confuses me why it shakes so much AND makes the noise if it were only the noise I'd say it's the clutch pushrod or the balll bearing that it rides on. It sounds to me like it is the thrust bearing though because it would make the hub off centered on the shaft.