A forum for owners of Yamaha TTR250 trail and enduro bikes!

dlee22 · Senior Member

Clutch plate explosion

ttr steve · Super Guru

Crikey Dan, you don't have a lot of luck at the moment cry

I have not seen any break like that before.

TTRfan · Super Guru

That is really strange (and unfortunate) Dan cry

It'll be interesting to find out if anyone else has such a thing happen and, if so, whether they know what caused it.

Presumably, from what you say, the clutch must have been working OK to get to the MOT and back. So what sort of sound was it making to alert you to the problem?

Brian

JOHNYBOY · Super Guru

most problems with clutch basket explosion kicking in gears without clutch mostly on motocross bikes when racing previous owner could have weakend it john

TTRfan · Super Guru

JOHNYBOY wrote:
most problems with clutch basket explosion kicking in gears without clutch mostly on motocross bikes when racing previous owner could have weakend it john

I was the previous owner John and am definitely not an MX racer wink

JOHNYBOY · Super Guru

bollocking accepted brian but probably other previos owners as we all know john

TTRfan · Super Guru

JOHNYBOY wrote:
bollocking accepted brian but probably other previos owners as we all know john

No bollocking intended John biggrin biggrin

Just saying I am very gentle with my TTR clutch and gear changes wink

Brian

JOHNYBOY · Super Guru

previous owners could have weakened it brian theres a time & a place for anything that we will never know untill it happens

dlee22 · Senior Member

I read somewhere about this happening when there was excessive wear on the basket (which this had)and that allowed the plates to move around.

There was also alot of rotational movement on the old basket i guess that in addition to the above helped it explode? What do the springs on the back of the plate do, is it some kind of dampening?

It does make me wonder if the standard springs were to have been replaced with heavy duty springs, would it have helped with the clutch basket wear as there would have been an increase of compressive force between the plates?

ttr steve · Super Guru

dlee22 wrote:
I read somewhere about this happening when there was excessive wear on the basket (which this had)and that allowed the plates to move around.

There was also alot of rotational movement on the old basket i guess that in addition to the above helped it explode? What do the springs on the back of the plate do, is it some kind of dampening?

It does make me wonder if the standard springs were to have been replaced with heavy duty springs, would it have helped with the clutch basket wear as there would have been an increase of compressive force between the plates?

I hope someone can answer that, as I am very interested.

TTRfan · Super Guru

dlee22 wrote:
I read somewhere about this happening when there was excessive wear on the basket (which this had)and that allowed the plates to move around.

There was also alot of rotational movement on the old basket i guess that in addition to the above helped it explode? What do the springs on the back of the plate do, is it some kind of dampening?

It does make me wonder if the standard springs were to have been replaced with heavy duty springs, would it have helped with the clutch basket wear as there would have been an increase of compressive force between the plates?

Hi Dan

Any chance of a photo to show what you mean about the basket wear please?

Cheers

Brian

dlee22 · Senior Member

Will do Brian, ill take a photo in the morning. Its the usual waves bit more extreme than normal.

I am putting my bet on the excess rotation, it seems like the strangest thing to find.

TTRfan · Super Guru

dlee22 wrote:
Will do Brian, ill take a photo in the morning. Its the usual waves bit more extreme than normal.

I am putting my bet on the excess rotation, it seems like the strangest thing to find.

Thanks Dan.

PS What do you mean by excess rotation?

TTRfan · Super Guru

dlee22 wrote:
Will do Brian, ill take a photo in the morning. Its the usual waves bit more extreme than normal.

I am putting my bet on the excess rotation, it seems like the strangest thing to find.

Any chance of the clutch photos please Dan?

Also, what do you mean by excess rotation please?

Brian

dlee22 · Senior Member

Hi there,

I have some photos, see attached.

They are much heavier groves that I have seen before, and are very very notchy when your finger tips are run along.

The biggest issue is that you have alot of movement when holding the basket still and trying to turn the large gear on the rear..... you can even move the springs with your fingers.

So strange, the excess movement is majorly noticible compared to the new unit that Brian kindly provided.

I need to now find my spare tab washer as I was struggling to bend the other side of the one I had.