157 replies to this topic

[m3psm]

Is this a regular problem? I'm about to get a new chain and sprocket for my Mk1.

I bought the TDM as a replacement for my ZZR1100 after the front sprocket came off at 120 doing untold damage and trying its best to spit me off. Don't ever need to experience that again

I pressume a new lock washer, locktight and correct torque setting will prevent any issues???

[Jez]

2 MkII's and I've not had this problem

That's a relief , I was starting to wonder if I should check mine.

I bought the TDM as a replacement for my ZZR1100 after the front sprocket came off at 120

That's uncanny. I had the same happen on a ZX10. Got away with it though - it just spun on the shaft.

[TonyDevil]

I pressume a new lock washer, locktight and correct torque setting will prevent any issues???

i believe so yes

[m3psm]

i believe so yes

Cheers

[ChrisG]

I suspect my problems stem from not having done the nut up tight enough when I replaced the sprocket some years back. General consesus seems to be to use a genuine Yamaha sprocket rather than an aftermarket.

[m3psm]

For the price of a front sprocket I can stretch to a genuine one. On the kwack the problem was re-using the old lock washer. They tear on the old fold, then the torque settings and locktite alone can't hold it.

[TonyDevil]

So, loctite it onto the shaft with 638, which will Sounds to me as though it came loose from loss of clamping pressure (not the nut coming loose) and then damaged the thread which allowed the nut to 'jump' the thread

there's no way it jumped the thread whilst it was still tight.

sorry GG, buts thats exactly whats happened, its pulled over the thread, i can see that from the damage to the nut
trying to find where i put the damaged nut so i can post a pic

So, loctite it onto the shaft with 638, which will prevent the rocking back and forth, will will prevent the loss of clamping pressure, which will prevent the nut jumping over threads and damaging them

I know its too late for you Toneski, but for others it is not
Cheap sprockets with excess clearance between it and the splined shaft would accelerate the wear effect of the sprocket rocking back and forth

there does seem to be less movement on the splines with genuine yammie sprocket

[ChrisG]

there does seem to be less movement on the splines with genuine yammie sprocket

There's gonna be feck all movement on mine by the time I've finished with that locktight.

Hope this sun holds out as I'm about to go and attack my nut with a dremmel

[Pict]

Halfords only sell sockets up to 32mm

The bigger branches sell larger sizes, including tough ones at about £7-8 that fit a half-inch square ratchet or an impact driver - maybe another way to attack tight nuts?

[ChrisG]

Right, I've performed a bit of grevious dremmely harm to the front sprocket nut



Note the distinct lack of thread on the inside.

I've cleaned up the thread on the output shaft and now the new nut goes on smoothly, however...

Am I right in saying the curve back on the my sprocket indicates I should fit a new chain and sprockets?



I guess nowhere's likely to have a set in stock that I can collect so I think I'm gonna have to put it back together with the old sprocket and only locktight the nut so when I get the new sprocket I can still take the old one off, then locktight the hell out of the new one.
edit: Tried Bykebits, Infinity and Woking Yamaha, nothing in stock

Recomendations for new chain? I'm thinking genuine Yam front sprocket, DID X ring and whatever Fowlers want to sell me for the rear.


edit: almost forgot, how tight should the fronty sprocket fit on the splines? Mine can rotate by a noticable amount, which could mean it allows it to slide around and wear.

Edited by ChrisG, 16 June 2007 - 10:31 am.

[TonyDevil]

Note the distinct lack of thread on the inside.same as what happend to mine

I guess nowhere's likely to have a set in stock that I can collect so I think I'm gonna have to put it back together with the old sprocket and only locktight the nut so when I get the new sprocket I can still take the old one off, then locktight the hell out of the new one.
yes that needs replacing, i would wait for a genuine yam one, but if desperate try "Motorcycle Parts Centre in Reading 01189594341". they wont have a genuine yammie one in stock, but they will have an after market
Recomendations for new chain? I'm thinking genuine Yam front sprocket, DID X ring and whatever Fowlers want to sell me for the rear.thats what i went for
edit: almost forgot, how tight should the fronty sprocket fit on the splines? Mine can rotate by a noticable amount, which could mean it allows it to slide around and wear.dunno, assume not much at all

is it possible the splines can wear over time?

[jht]

Output shaft replacement class anyone..........

[ChrisG]

I'm favouring the stick it back together now and order the correct bits from Fowlers approach. Just tried several places and nothing in stock so may as well take the time to get the right bits.

Ordinarily I'd leave it in peices in the garage for a week but I could do with using it for commuting for a couple of weeks to ckeep the mileage down on the cage.

Output shaft replacement class anyone..........

That's gonna need more than 3 packs of hobnobs, 2 packs of Jaffa cakes a pack of jammie dodgers, and pack of cookies!

Edited by ChrisG, 16 June 2007 - 10:47 am.

[TonyDevil]

Output shaft replacement class anyone..........

That's gonna need more than 3 packs of hobnobs, 2 packs of Jaffa cakes a pack of jammie dodgers, and pack of cookies!

....and more than a day

but i'm game for a laugh

[ChrisG]

Hmmm, Fowlers will only do genuine Yamaha parts, is the X-ring going to be noticable better than the genuine one?

Edited by ChrisG, 16 June 2007 - 11:48 am.

[m3psm]

I've never had or seen a spline wear when the sprocket was securely fixed in place. I think the wear is more likely because the sprocket was moving around on the shaft side to side after the nut came loose.

The teeth on the front sprocket are well worn. The rears hook over like that first with the chain being out of adjustment. This then stretches the chain more and then starts to hook the teeth on the front sprocket.

My rears have hooked and chain is stretching now so need to replace it fairly sharpish because it'll put more strain on the sprocket nut as the chain wont seat properly on the sprocket.

The easiest way to tell if you have hooked sprockets is to roll the bike backwards. If it's past it's best you'll hear a clicking noise where the chain is jumping into place.

[ChrisG]

Yikes, genuine yam front sprocket is nearly £50 compared to less than a tenner for a pattern one, and it's going to take a week as Fowlers haven't got any in stock.

Oh well, it's on order and my x-ring chain and pattern rear sprocket are on thier way form M&P

[Jez]

Recomendations for new chain? I'm thinking genuine Yam front sprocket, DID X ring and whatever Fowlers want to sell me for the rear.

Last change I bought a super dooper DID X-ring kit from M&P - cost about £120. Has been on now for nearly 5k miles and adjusted just once at 1k miles. (BTW did I hear that DID do a chain that is guaranteed for 25k miles, or was I dreaming?)

I do beleive in investing in good chain and i have never bought genuine in my life.

As for the front sprocket I cannot comment as I have a mk2 but is it possible to pack out any gap behind the sprocket with extra locking washers or plain ones?

[ChrisG]

As for the front sprocket I cannot comment as I have a mk2 but is it possible to pack out any gap behind the sprocket with extra locking washers or plain ones?

Not convinced about this sprocket thickness isue but going for a Yam one just in case. Sprocket sits on the splines and there's a section of shaft behind, so the shoulder it sits against is probably too small to have another washer on.



I had 2 washers between the sprocket and the nut though so that should have the same effect as a thicker sprocket.

I've put the old sprocket back on for the time being with a new nut and locktight on the nut only. Should have the new chain and sprockets by next weekend which should be less than 700 miles away, I'll then use the locktight on the sprocket as well and accept that I'll need a bearing puller to get it off again.

The old chain is a DID X-ring has been on for 25-30,000 miles (with a scott oiler)