Bad noise after rebuild

Mr-Wolf said:

Hillsy I think that is exactly my problem, I think I remember see divots in the one way bearing! Any chance you or anyone know where I can get a replacement?

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No idea where you can buy new, but we used to use a die grinder to take the notched out of the ramps and they were good again. You just have to be careful not to take off too much or mis-shape them or else they're fubar'd.


Not sure about your one, but with the Kawasaki's and Suzuki's you could take off the backing plate to make it easier to mill.

hillsy said:

No idea where you can buy new, but we used to use a die grinder to take the notched out of the ramps and they were good again. You just have to be careful not to take off too much or mis-shape them or else they're fubar'd.


Not sure about your one, but with the Kawasaki's and Suzuki's you could take off the backing plate to make it easier to mill.

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Wouldn't smoothing out the notch cause it to not fit properly? Or do you just smooth out from right side of divot to wide side, instead of left side of divot to wide side.

As the roller moves down the ramp it is pushed in against the centre shaft. If there is a divot where they meet it will not allow the roller to engage properly and the roller will spin and the starter clutch slip. You need to remove the divot and re-shape the ramp to the same angle / shape it is supposed to be. You have to be careful and only take out the minimum amount necessary to remove the divots.

there is a bunch of starter clutches for sale on ebay they are <40 bucks

Mr-Wolf said:

https://youtu.be/FhmrT7pdKCA

Here is a video I took of the old starter clutch with new rollers and such. I'm noticing that only 1 roller depresses at a time

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Only just able to view this now - looks like either the ramps are really worn out or the rollers are the wrong size. The rollers shouldn't be able to go right to the end of the cavities - they should all stop somewhere in the middle.

cxman said:

there is a bunch of starter clutches for sale on ebay they are <40 bucks

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Where are you finding these! I haven't been able to find anything for my bike, I have seen them for others.

hillsy said:

Only just able to view this now - looks like either the ramps are really worn out or the rollers are the wrong size. The rollers shouldn't be able to go right to the end of the cavities - they should all stop somewhere in the middle.

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Rollers are brand new and for that bike, roughly the same size as the old ones. Id be willing to be that one way bearing is just that worn out.
how likely is it that the starting gear race has worn down vs. the brass one way bearing face? I am trying to decide between just getting the oneway bearing vs getting bearing, starting gear, reduction gear.

One of those rollers must be hung up on a "divot" as it's failing to move back and lock up. The housing is hardened and would have to be ground back and should be OK after that. If not, get a complete assembly.

The circular piece at the centre of gear the rollers lock onto is smooth?
They get damaged with 'dents and cannot lock in place'
In my experience it's incredibly common
If it's been ground smooth that could account for rollers going too far up the ramp?

The rollers and the circular piece are normally hard chromed (like fork stanchions). You'll see any wear on them pretty easily, but it's usually the ramps that take the punishment.


I'd try and smooth out the ramps first (you've got nothing to lose) and if that doesn't work then you may just have to bite the bullet and buy another one. Second hand is a bit of a lucky dip but you'd probably get a better one than what you have right now.

teazer said:

One of those rollers must be hung up on a "divot" as it's failing to move back and lock up. The housing is hardened and would have to be ground back and should be OK after that. If not, get a complete assembly.

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hillsy said:

The rollers and the circular piece are normally hard chromed (like fork stanchions). You'll see any wear on them pretty easily, but it's usually the ramps that take the punishment.


I'd try and smooth out the ramps first (you've got nothing to lose) and if that doesn't work then you may just have to bite the bullet and buy another one. Second hand is a bit of a lucky dip but you'd probably get a better one than what you have right now.[/wuote]

crazypj said:

The circular piece at the centre of gear the rollers lock onto is smooth?
They get damaged with 'dents and cannot lock in place'
In my experience it's incredibly common
If it's been ground smooth that could account for rollers going too far up the ramp?

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Current game plan, I got a used roller housing? (The part with ramps)
I will take the damned thing apart again and replace the roller housing and rollers, springs, caps. I'm going to take the starter gear to my brother and have him slap it on his lathe and see how true it is. If it's spec slap in and go, if not have it trued it and temper maybe? How does that plan sound?

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Ok, I have attached more videos........
still having a problem, I replaced rollers, springs, caps and one way bearing! Took the sprocket to a machinist and had him measure it and it came out perfectly fine.
I re assembled last night, pinched a damn wire and called it a night. Got up and fixed it this morning and gave it a try. NO DAMN GO! Needless to say I am pissed....So again I take the pan off and take this video so you guys can really see whats going on.

https://www.youtube.com/watch?v=Cv4KdfXEmNw

https://www.youtube.com/watch?v=7N8nU572NYc



Also, might as well change this to the "WHAT THE F*** IS WRONG WITH BIA NOW" Thread.......

You need to either replace the part with the indented ramps or reshape the ramps. No amount of throwing other parts at it will fix it otherwise.

hillsy said:

You need to either replace the part with the indented ramps or reshape the ramps. No amount of throwing other parts at it will fix it otherwise.

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Hillsy, I replaced the one way bearing already (part with ramps) I had the sproket face measured for roundness and deformation too.

Replaced with new or second hand?

hillsy said:

Replaced with new or second hand?

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Couldn't find a new one for under $300, so I bought a used one off a 3wheeler. It looked basically new, with no dents or deformed. I forgot to snap a picture but all the rollers landed in the middle, no bottomed out.

That's most unusual. Skidding like that is not uncommon with worn rollers or soft springs or worn out ramps in the sprag clutch, but in one that is all new/good is odd.

I was tempted to suggest that the oil had too much molybdenum in it but it's not a simple friction device. It's also a mechanical ramp that forces the rollers into contact with the gear drive from the starter. Typically the ramp/cam part is bolted to the crank and the gear is driven by the starter motor. In this case I believe that the clutch sits on a splined shaft. In your case that starter gear is slipping and not being grabbed by the rollers.

That suggests perhaps the springs are damaged ( I think you said they were just replaced, or the rollers are moving too far because they are undersized and you mention that they stop half way, so that is probably eliminated as a cause. Or the rollers/gear hub are too smooth and slippy, which sounds ridiculous I know, but something odd is going on there.

It seems that the rollers are skidding on the gear boss. You could try to scuff the surface slightly to see if that helps and inspect the rollers and springs again. Did you fit new spring end caps on teh new springs or were teh originals all good?

hillsy said:

Replaced with new or second hand?

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teazer said:

That's most unusual. Skidding like that is not uncommon with worn rollers or soft springs or worn out ramps in the sprag clutch, but in one that is all new/good is odd.

I was tempted to suggest that the oil had too much molybdenum in it but it's not a simple friction device. It's also a mechanical ramp that forces the rollers into contact with the gear drive from the starter. Typically the ramp/cam part is bolted to the crank and the gear is driven by the starter motor. In this case I believe that the clutch sits on a splined shaft. In your case that starter gear is slipping and not being grabbed by the rollers.

That suggests perhaps the springs are damaged ( I think you said they were just replaced, or the rollers are moving too far because they are undersized and you mention that they stop half way, so that is probably eliminated as a cause. Or the rollers/gear hub are too smooth and slippy, which sounds ridiculous I know, but something odd is going on there.

It seems that the rollers are skidding on the gear boss. You could try to scuff the surface slightly to see if that helps and inspect the rollers and springs again. Did you fit new spring end caps on teh new springs or were teh originals all good?

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I took it all apart again, I'm really getting very good at this. This round took me 1hr including making another clutch but tool cause I broke mine.
In the pictures you can see I found it had pegged the caps all the way back and locked them there! So I took a finish nail from the back to unplug them (had to use a hammer, they were stuck that hard) so here is what I found. The rebuild kit I linked earlier the springs and caps are not correctly sized. The caps are all larger then the ones I have on the used part I bought and the stings are shorter then the oem ones I ordered, the rollers however are perfectly sized.

So this is what I have done now and you can see the results in the video below. I have the used one way bearing I bought with two new oem springs and one from the rebuild kit (I know it's a bit shorter however I pushes the cap the same distance out and had the same tension (all the used ones I have a weak as all get out) the caps from the used one way as they fit perfectly and show no signs of wear, and the 3 new rollers and pin from the rebuild kit I ordered. You can see how this all works in this video.

https://youtu.be/HB6PJLwvkII


Is there anything else I should check while it is all apart? I am getting good at this but every time I take this apart I fear I will destroy another gasket (already replaced twice) and I am really tired of doing it and want to get on with fixing the other inevitable broken stuff lol.

Progress. The springs do not have to be very strong. Just enough to push the rollers out and after that they just grab. Once the motor fires, centrifugal force pushes the rollers back against the springs to disengage the starter motor. You can use the old spring caps or get some new ones if necessary. My guess is that the same springs rollers and caps are used in a million different bikes.

Doing this on a GPZ today, you really need to look things over, the starter gear surface the those rollers grab onto can get notched pretty bad and be worn down enough that no new rollers will bite.

Look close you can see I've been sanding off the ridges on mine. I went ahead and ordered a whole used shaft and starter clutch soup to nuts, but I have nothing better to do so for $60 I can do it again lol

Look at the rollers



I was able to pull it all on a table and up on the center stand


Just make a big pile it's all good lol