FJ gear alignment query

[millosman]

Hello everyone.

Again I would appreciate a little guidance please.

My 1200 3XW motor is currently dismantled.
Having fitted a rebuild kit to the starter clutch I started to reassemble but I've noticed something that looks wrong to me.

I've uploaded two pics. One shows the oil pump idler gear meshing nicely with the starter clutch drive.

I've noticed that both of these pinions have lateral movement on their shafts, to such a degree that pushing one to the left and the other to the right, the meshing teeth are only half engaged.

Please refer to pics. I can upload a short video that demonstrates this better but it's 56mb which may be too large for this site?

I can't understand why this lateral movement is present or how to get rid of it.
Any ideas anyone?

Thanks in advance
Andy

[FJ_Hooligan]

Judging by the wear pattern on the gear teeth, it looks like that's how they have been meshing all along.

[racerrad8]

Andy,

As David already mentioned the wear pattern indicates that is how they have been wearing. Did you have the start drive shaft fully seated when checking?

I can't recall what controls the lateral movement and I don't have anything apart to be able to look at it. I would have had one to check out but we put it back together on Friday...

If you look at the gear alignment it looks the same.

Secondly, neither of those gears are associated with the oil pump. The idler gear only meshes with the starter and offers the gear reduction needed to start the engine.

If it was me, I would not worry about it based on the previous wear indication and the similar alignment of the engine I just assembled.

Noel should be along shortly and should be able to offer you the definitive, industry answer. 

Randy - RPM

[Pat Conlon]

That does not look right to me, it might be ok, but I can't believe Yamaha designed it that way.

[millosman]

Andy,

As David already mentioned the wear pattern indicates that is how they have been wearing. Did you have the start drive shaft fully seated when checking?

I can't recall what controls the lateral movement and I don't have anything apart to be able to look at it. I would have had one to check out but we put it back together on Friday...

If you look at the gear alignment it looks the same.

Secondly, neither of those gears are associated with the oil pump. The idler gear only meshes with the starter and offers the gear reduction needed to start the engine.

If it was me, I would not worry about it based on the previous wear indication and the similar alignment of the engine I just assembled.

Noel should be along shortly and should be able to offer you the definitive, industry answer. 

Randy - RPM

Thanks for your advice Randy/David.
I can see the wear marks as you pointed out. The reason for the strip down was noisy starter chain and a kind of zippy sound when the starter is used. Difficult to describe the sound in text.
It am wondering if these misaligned teeth could be slipping?
The position of the starter clutch shaft is dictated by the location of the bearing on it's shaft so if the bearing isn't in the right position this would cause misalignment I think.
Whilst the shaft is in as far as it goes, looking at the internal side it does not protrude fully into its bearing.
The smaller pinion can move over a millimetre laterally on it's shaft too. I guess a shim could be used to keep it in the correct position.
Thanks again all.
Andy

[Pat Conlon]

Andy, it was reported by Rolf (Old Rider) in his excellent Splitting the Cases post, that a loose starter chain drags on the oil jet causing a god awful grinding noise.
See posts #117 and 214
http://www.fjowners.com/index.php?topic=18143.210

Better pictures of the chain damaged oil jet are here
http://www.fjowners.com/index.php?topic=18400.msg185849#msg185849

In the newer XJR's Yamaha revised the oil jet in this location to a stubby design:
Picture courtesy of Rolf (Old Rider)


Thank you Rolf, you spent hours and hours on your posts, and speaking on behalf of our forum members, we really appreciate your posts and all that work you put in to share your knowledge with us.

[millosman]

Andy, it was reported by Rolf (Old Rider) in his excellent Splitting the Cases post, that a loose starter chain drags on the oil jet causing a god awful grinding noise.

Hi Pat. Thx for your reply. I was aware of the starter chain rattle which is why the motor is in bits.
I've changed the chain and fitted new parts to the starter clutch in a bid to eradicate this.

Along the way I noticed the misaligned teeth and would like to sort this out before putting it back together.

Has anyone noticed this poor alignment in their motors and if so how was it corrected?

Thanks again Pat.

Andy.
PS does anyone know a source for front engine rubber mounts part nos  90387-207W3? Seems this is discontinued here in UK.

[Troyskie]

Andy,

My cases are in a similar state.

I've had a look t the wear on both of my gears. The little one is almost identical. The large shows equal wear. This engine has around 68K irf the ODO is to be believed. I believe it as the crank etc. are in as-new spec on the bearings.

I'm a novice at this, but think could Yamaha have allowed these gears to 'float' to allow for torque?

It is surprising to see the same amount of wear on the small gear as mine.