MT250 Clutch Issue:

[AimlessMoto]

Quick rundown:

Installed everything 100% correct to manual.

When the clutch cable is installed, adjusted, and locked in... I can pull the cover off the clutch adjuster bolt (the aluminum screw cap) and see the clutch moving when I pull the lever.

That being said, the clutch does NOT disengage. I can put it in first gear, and push forward and the engine turns over whether I pull the clutch in or not.

If I start the bike... pull the clutch... and drop it into first... the bike jerks slightly and then the clutch slips.

If the rear wheel is off the ground... the rear tire will spin when put in 1st no problem.

With the wheel on the ground, I can sit on the bike running... pop it into first, and rev the motor up to about 1/2 throttle, shift into second, rev up, shift into third... as if it's driving... but it's just sitting there... making noise and not moving.

THERE IS ABSOLUTELY NO NOISE out of the transmission... No grinding, no whizzing, no hum... nothing sounds out of the ordinary.

It's almost as if both the clutch springs are too weak, and the clutch plates are stuck together.

I've tried removing the clutch cable completely and I get the same result... the clutch slips as soon as you pop it into first.

...

I've never dealt with a clutch this bad... so I don't know if it's 100% clutch or not. But there is definitely a disconnection between the clutch and the final drive shaft.... everything else in the transmission/engine is engaged as normal.

Any ideas?

[Paul_E_D]

You need to measure all the plates/fibers and check against spec. Also check the pressure plate for wear. THere is usually a measurement you can check there.

Some dragginess is normal, so your first problem is a non problem. Many two strokes are a little hard to push in gear even with the clutch squeezed and will turn the motor.

If I understand correctly your bike won't go forward in gear with the clutch released. Measure all the components...

[AimlessMoto]

I just took everything apart, unfortunately... I read your post AFTER the fact.

Everything mates up and works properly... however, I feel as though the plates are worn down beyond adjustment.

I backed the adjustment screw out so it's just touching the pushrod... and loosened the cable 100%... it still drags some, but it will not clamp strong enough to move the bike with rider on it... or standing next to the bike...

It grabs a LITTLE at low rpm only... but not enough to propel you forward.

Looks like I need a new clutch and springs.

[Paul_E_D]

Measure the springs as well. Only replace the parts that are out of spec.

[AimlessMoto]

Friction Disc Spec: 2.68mm - 2.75mm : Limit is 2.4mm thin.
Clutch Spring Spec: 41.4mm - 43.2mm: Limit is 40mm long.

There is no spec on the metal clutch plates... but none of them are warped.

The "Troubleshooting" section of the manual states the following:

Clutch Dragging: Maladjusted clutch springs, maladjusted clutch cable: Readjust.
Clutch Slippage: Maladjusted clutch cable: Readjust.

All other possibilities for both are:
Warped clutch discs: REPLACE
Worn clutch friction discs: REPLACE
Burnt friction discs: REPLACE
Worn clutch springs: REPLACE


So.... considering there is nothing out of adjustment... my only option is to replace.

Parts are on order.

[Paul_E_D]

Are the correct number of plates in there? You haven't found your problem unless the steels in there are the wrong size, or severely warped. When the clutch is released is there slack in the cable?

[csmutty]

Dan...as I posted on BoRn, are you sure that you used an oil that does not contain friction modifiers? When I owned this bike and rode it, the clutch never slipped on me and was very solid.

[AimlessMoto]

Are the correct number of plates in there? You haven't found your problem unless the steels in there are the wrong size, or severely warped. When the clutch is released is there slack in the cable?

Yes... 7 friction plates, 6 steel discs.

When the clutch is released, there is NO slack on the cable. The discs are not warped.. I did double check that before re-installing everything.

To comment back on Christian, yeah man. I totally saw the other post on BoRn.

100% sure right oil... 100% sure everything else...

It's just that the clutches were left in an uninsulated barn for about 18 months out side of the motor... so I'm 99% sure that had an adverse affect on their integrity.

Oh well. If I get a new one, at least I know it's new, god knows, even if the original was 100% fine when Christian sold it, it was still probably stock.

There's also no 'abusive' wear in the motor. It looks brand new, no gouging on the basket forks, and everything moves freely...

[Kurlon]

Does this bike have a second adjuster on the pushrod assembly, under that cap? That needs to be adjusted so cable loose, there is a quarter to half turn before it gets resistance from hitting the clutch pack. If it's too tight, the clutch will never engage.

[AimlessMoto]

Believe me... EVERY adjuster has been fiddled with repeatedly.

The pushrod adjuster, the cable near the cam and the cable at the lever.


All of it.

[Paul_E_D]

THere should be a little slack in the cable when the clutch is released. Are you using stock controls and cable?

[AimlessMoto]

Yes. I've taken the cable completely off and loosened the adjuster screw so it doesn't touch at all... just to see and it STILL slips.

New clutch will be here next week. No worries.