Kawi2strokes.com Forum

SOOOO Ive been working on the H2, new pipes and some other upgrades . Im getting the swingarm and the new linkage powder coated (and some other bits and pieces). During the tear down I noticed this.....

https://youtu.be/JFVg9fM6ytE

I have a plan, Im going to machine off the back of this sprocket (where the splines are), weld two sprockets together, machine the teeth off them to fit the current offset sprocket and weld them to that. Then machine down the spacer and machine the thickness of the two sprockets that are welded together get it all aligned. This will allow it to grab more spline on the shaft. Or something like that. Im going to talk to my machinist friend Tuesday and see what he thinks.

I could just get another sprocket made but if you look close the splines on the shaft are getting a bit worn too. But something needs to be done for sure!!

Probably lost the hardening when they welded it. Just remember that when building a new one.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

Good point John! I assume someone could re-harden it...maybe.

When tightening the nut on the sprocket the ft lbs of torque does not get transferred to the collar or the bearing race, it gets transferred to the spline shaft correct??

In other words the stacked width of the collar, the o ring, and the bearing race does not have all the foot pounds of torque of the nut on them, it is simply all "trapped" in place by the sprocket. Would there be a clearance number to shoot for say .001" or .0005"??
Or is it all on force all on the bearing race?

I go with two issues, as John mentioned, the hardening of the sprockets was compromised by the welding.

Second, and more serious, the sprocket nut was set too low on torque, allowing the sprocket to migrate on the output shaft splines. As the sprocket was rammed into the stops of the splines under normal operation, acceleration/deceleration vs bike weight, the splines on both the sprocket, AND output shaft were compromised, and now, BOTH spine sets will need to be replaced, sprocket AND output shaft.

At least, that is what I saw in the video.

On the sprocket nut torque, the nut loads as thus, thrust face on output shaft, to inner race of the bearing, to spacer, to sprocket, to lock washer, to inner face of nut, to output shaft threads. The splines are really not in the torque plan for tightness of the sprocket set to the output shaft, but do control front to rear torque effect, when the load is tight, a little bit loose so the sprocket can ge moved forward to rear and reversed, and impact wear will result, as seen in the video. Add any transmission oils that get past the sealing O ring on the shaft, the torque thrust gets easier to accomplish with a loose sprocket nut.

I agree both the shaft and the sprocket are compromised. However it is not in the cards to pull and replace the shaft now($$$) I am hoping by grabbing a bit more spline it will get me though this summer to next winter then it will most likely be a teardown. But I am concerned.

I have some sprockets on the way so I will see how much play is in them and the splines with new sprockets. And I will ask my Machinest buddy, he can get stuff cut very precisely, maybe he can measure what's there and have something cut to fit tightly on the splines, but I doubt it. Also drag guys used to "shim" the splines when they wore down, not saying its a good idea just I remember guys doing it.......

The hardness must have been compromised by the welding, once John mentioned it it seemed obvious.
The nut was to spec I almost couldn't get it off, I think maybe there is a problem in how I had it stacked and it wasn't putting the load where it needed to be. Its all weird custom stuff so maybe I had it goofed up from the start.

Tuner are you saying the the 85 ft lb of torque does load the collar/spacer and the inner race of the bearing??

And yes it was leaking just a bit of fluid through those seals which are being replace. So that may have made it worse???

"Tuner are you saying the the 85 ft lb of torque does load the collar/spacer and the inner race of the bearing??"

Yes, it is possible, IF the "stack" of the compressed parts is shorter than the nut will compress all the way down the stack. Some of these nuts have a recess cut into them, to make sure that the stack is tightened all the way with the nut torque spec. IF the stack is just at the distance the nut has to move, and it stacks as well, with a lower crush distance, then, yes, the nut torque will be fine, peer spec, but the parts stack will not have that torque value. This would take the nut hitting the splined area just right to not set torque correctly on the parts stack.

"And yes it was leaking just a bit of fluid through those seals which are being replace. So that may have made it worse???"

Possible on the making it worse if the sprocket and parts weren't tight as they should be, but, from the seal to collar, or, through the O ring on the shaft inside the collar??? BIG difference, seal, messy all over, O ring, will show paths on the sprocket faces that oil has permeated out the splined area, and flung out to the outer diameters of the sprocket, also making oil paths that look like they came from each side of the sprocket. Is there a two line oil path all the way around the sprocket path on the cases??

Simpler, it is a lot like a water hose for the main seal, water all over the place, hose with a round pattern water path being flung out in a circle, water goes out in a circular direction from the center of the wheel on the sprinkler head.

EDIT: I just took another couple of looks on the video, and I don't think the O ring on the shaft is the oil leak, looks more like the seal itself. Also, put the stack back together and leave the locating tab in place on the sprocket, measure the distance from the end of the splines poking out of the washer, and compare them to the relief in the inner side of the nut. Example: stack, .150, nut, .155, or stack .159, and the relief .200, what do you have????

Thanks Tuner!
I will be measuring carefully. I think I have had this wrong from the start. I am pretty sure the nut was hitting the splines and not properly tightening down the assembly. Nothing I’m working with is stock, so when I put it together originally I tried to understand it but I don’t think I got it right.
I will look at this very closely now!

I looked at it and yes the nut was bottoming out on the splines, not putting nay pressure on the stack.
So when I assemble it I will be sure to get the torque to transfer to the collar.

Now the question is how to re-harden the welded sprockets!

There is a right way, and a wrong way, and a get by until fall way........LOL. You have more than enough interface to last a riding season. To get by I would fit some Piano wire in the slots to tighten things up and enjoy the Summer.

_________________
Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

Bingo on the nut
Good call on wire temp fix

cliff

ps
weld softening? NO

these things were hammering each other HARD for a while

they were both hard and now, harder, and harder to fix