Space behind primary?

[saskattakman]

Yep...same as mine...

One hard SNAP on hard accel did it for me...just once. When removing the primary, I can see a 1mm space there(outer race) where mine moved in. My offset went from NEW at 61mm to 62mm....I knew I didnt measure it wrong.lol

I would assume the splines would bottom out, not allowing the stub to move inward after 1mm or so....but its looking like more then that if sheaves end up hitting bolts. grrrr

Dan

when the stub shaft bearing is all the way out and the stub shaft itself is all the way into bearing there is approx 1.5mm distance from stub shaft to crankshaft..this takes you over the 61.1mm offset when a belt blows and moves the stub in.

 

[Beerman]

This is very interesting. Seems like two issues from this stub. Subscribed. Is there anything else that can be done? Is green loctite going to work for the long haul?

It's strong stuff for sure, I guess we'll see the next time I pop a belt, which is hopefully never. I'll be testing a new combo that @ClutchMaster has been helping me with - if this works he and I will post up the details, it's an ongoing trial and error to get belt life to a reasonable level.

 

[Fast]

Its a stub shaft

Dan quick question when you had the stub shaft out did the bearing move on the shaft?did you have to press it on until it bottomed out? or was that ok.

 

[ROCKERDAN]

Dan quick question when you had the stub shaft out did the bearing move on the shaft?did you have to press it on until it bottomed out? or was that ok.

Bearing moves inward, shaft stays put into bearing....at least that's how mine moved.


Dan

 

[Beerman]

Bearing moves inward, shaft stays put into bearing....at least that's how mine moved.


Dan

Same here - where the shaft is pressed into the bearing it seems super solid, where the bearing is pressed into the housing, not so much. But after spending an hour B.S.ing with Knapp at his place, he hooked me up, I don't it expect to move now with the Loctite 638.

 

[Fast]

Bearing moves inward, shaft stays put into bearing....at least that's how mine moved.


Dan

Just looking at the picture of the stub shaft,the bearing is bottomed out and held in place with a collar and four bolts does the spline bottom out as well,just dont understand how the bearing could move if the spline doesnt bottom out wouldn't the shaft move away from the bearing inward

 

[1nc 2000]

How much clearance is there between the stub shaft and crank? Will the stub shaft bottom out on the crank as it moves inward?

 

[ROCKERDAN]

Just looking at the picture of the stub shaft,the bearing is bottomed out and held in place with a collar and four bolts does the spline bottom out as well,just dont understand how the bearing could move if the spline doesnt bottom out wouldn't the shaft move away from the bearing inward

If I understand you, the splines have approx 1.5mm of space, so the entire stub can move inward on those splines onto the crank itself further inward. Mine has moved 1mm or so.

So the ENTIRE stub WITH BEARING all move inward.

The outer race, where it seats into the housing(with the 4 bolts connected to block) is the area of movement, where the outer race 'slides' inward. You can remove primary and see this space if it has moved.

Sounds to me, like YAM is likely using loctite bearing retainer compound on the stub to bearing seat, but NOT using any compound on the bearing outer race to housing seat.

Dan

 

[ROCKERDAN]

How much clearance is there between the stub shaft and crank? Will the stub shaft bottom out on the crank as it moves inward?

Im figuring approx 1.5mm from what ive read(total)

 

[Fast]

If I understand you, the splines have approx 1.5mm of space, so the entire stub can move inward on those splines onto the crank itself further inward. Mine has moved 1mm or so.

So the ENTIRE stub WITH BEARING all move inward.

The outer race, where it seats into the housing(with the 4 bolts connected to block) is the area of movement, where the outer race 'slides' inward. You can remove primary and see this space if it has moved.

Sounds to me, like YAM is likely using loctite bearing retainer compound on the stub to bearing seat, but NOT using any compound on the bearing outer race to housing seat.

Dan

That sounds like a design flaw you would think the outer race would fit against a flange like a machined surface,wonder if the hurricane shaft fits tight in the spline or does it still have 1 to 1.5mm clearance too

 

[ROCKERDAN]

That sounds like a design flaw you would think the outer race would fit against a flange like a machined surface,wonder if the hurricane shaft fits tight in the spline or does it still have 1 to 1.5mm clearance too

Well how would you install the bearing then? It is pressed in and seats against flange, Gotta be pressed in from one side or the other.

I think the splines are not meant to be tight(end to end).

Dan

 

[Fast]

If I understand you, the splines have approx 1.5mm of space, so the entire stub can move inward on those splines onto the crank itself further inward. Mine has moved 1mm or so.

So the ENTIRE stub WITH BEARING all move inward.

The outer race, where it seats into the housing(with the 4 bolts connected to block) is the area of movement, where the outer race 'slides' inward. You can remove primary and see this space if it has moved.

Sounds to me, like YAM is likely using loctite bearing retainer compound on the stub to bearing seat, but NOT using any compound on the bearing outer race to housing seat.

Dan

Im not a bearing expert but i thought you can only have 1 bearing fit

Well how would you install the bearing then? It is pressed in and seats against flange, Gotta be pressed in from one side or the other.

I think the splines are not meant to be tight(end to end).

Dan

Could this be a saftey concern from yamaha if a belt blows its not stressing the crank by slamming against it

 

[ROCKERDAN]

Im not a bearing expert but i thought you can only have 1 bearing fit

Im not sure I follow you...

 

[Fast]

If I understand you, the splines have approx 1.5mm of space, so the entire stub can move inward on those splines onto the crank itself further inward. Mine has moved 1mm or so.

So the ENTIRE stub WITH BEARING all move inward.

The outer race, where it seats into the housing(with the 4 bolts connected to block) is the area of movement, where the outer race 'slides' inward. You can remove primary and see this space if it has moved.

Sounds to me, like YAM is likely using loctite bearing retainer compound on the stub to bearing seat, but NOT using any compound on the bearing outer race to housing seat.

Dan

Im not a bearing expert but i thought you can only have 1 bearing fit

Well how would you install the bearing then? It is pressed in and seats against flange, Gotta be pressed in from one side or the other.

I think the splines are not meant to be tight(end to end).

Dan

The bearing would be installed on the shaft then slide the whole assembly in until it bottoms out against the "flange" then put in the 4 bolts on the outside flange

 

[Fast]

Same here - where the shaft is pressed into the bearing it seems super solid, where the bearing is pressed into the housing, not so much. But after spending an hour B.S.ing with Knapp at his place, he hooked me up, I don't it expect to move now with the Loctite 638.

What about making a brass washer 1.6mm thick or what ever thickness needed and putting it between the crank and stub shaft?