TOPIC:

Initially I've messaged the seller asking for the width of the roller, and confirmation that it has a roller bearing. I'll order one if I receive a favorable reply.

Looking forward to that detail !

I wonder what made Kawasaki choose to use a needle roller on this part for the 1300, but a plain bush on the  650 / 900 / 1000.  

I wonder that as well. 

I just realized that there's an issue with the 13mm pin.  It has no c-clips to retain the Pin !  Not insurmountable, but a pain.

For what it's worth I found this:
 
www.google.com/url?sa=i&url=https%3A%2F%...xfICFQAAAAAdAAAAABAJ

 

What I know about bearings-
Given the choice between a plain bearing and a roller bearing be it ball or needle bearing, If an oil wedge can be guaranteed, a plain bearing will always outlast a roller bearing but the key is an oil wedge which usually means an oil fed bearing. Sometimes, when the load is light a flooded plain bearing will be fine.
If you take a ball and roll it around on the table with your hand, little friction is felt no matter how hard you press on the ball. Then take your hand and press on the table and try to move it around. Obviously friction is felt. Then squirt some oil on the table and move your hand around. Little to no friction. Obviously you're not going to do this but you get my point. Your hand on the table without a ball is similar to a plain bearing without an oil wedge or being flooded with oil.
In the case of this application, the needle bearing is more desirable since the only lubrication is from any oil that manages to find its way to the bearing. A couple of drops once in a while will provide enough lubrication /cooling for the bearing. Bear in mind that this tensioner being almost the same size of the drive sprocket on the secondary shaft , this tensioner will be spinning at crankshaft speed as high as 8000 rpm. That's a lot to ask of a plain bearing that's not oil fed and not flooded in a bath of oil.

If you're interested- At the nuclear power plant I worked at, the 450 Mw generators were powered by 3 low pressure steam turbines and one high pressure steam turbine. The rotating mass  of the generator rotor and the 4 turbine shafts was 450 tonnes spinning at 1800 rpm. The rotating mass rode on 12 plain bearings.
There was two oiling systems to feed oil to those 12 bearings. The Jacking oil system literally lifted the rotating mass off of the plain bearings and then the Lube Oil System provided the flooding oil to allow the bearing/shaft interface to create an oil wedge and maintain a fluid coupling between the moving parts. Once, on start up after a unit outage, an operator put the rotating mass on turning gear and forgot to fire up the jacking oil first. In 2 revolutions of the rotating mass, he managed to wipe out the 12 plain bearings (which were babbitt bearings). The outage had to be extended by 5 weeks while we changed out the bearings at a nominal cost of $ 1.5 million dollars a day lost earnings. The boss was not happy. Neither was the maintenance staff who had to work in the turbine hall mid summer in a room temperature of 45-50 deg. Cel. 24 hours a day.

Interesting read kawboy. So I take from this that those turbines are about the same mass as our bikes

 

I've spent too much time on the CCT "thing".  Any more and I'll simply be goin' round in ever-increasing circles.

My last comments were about my preference for the J78 bearing and conceded a bushing would be fine. 
The glitch in the conversion; using another Kawi's rubber roller, is slightly complicated by two details.
1)  The  rollers "Shaft" - (per the manual)  must be held captive with external snap-rings so it can't come fall out !
 2) The length cannot exceed the OEM's or it won't fit into the cark-case.
3) The Shaft can not rotate in the frame holes.  The OEM 11mm Shaft deals with this with one end being machined to fit a semi-circular hole in the CCT frame. 
4) Using  the alterative roller ( Yet to learn it's width) will require a new 13mm Shaft to be fabricated C/W snap-rings and that semi-circle detail on one end. 
While in a lathe the rubber tire dia. can be reduced to 32mm.  

For myself: Either way requires the involvement of a machine shop.   $$$ are not the issue. A few hundred $ to get another 41 years/ 93,000K is excellent value.  
So thanks kawboy for the bearing lube enlightenment.  It's back to the J78 !
Any other ideas, comment/suggestions are welcome............... 
  

Stupidly, I didn't realise that - unlike the 1300 - the KZ900 / 1000 has a GUIDE WHEEL ( which is what Kawboy illustrated a few posts back)  , with plain bushing, which I was confusing with the TENSIONER wheel ( in the tensioner assembly)  So I wonder if the wheel in the tensioner assembly does have a factory fitted needle roller?   But could that guide wheel be bored out to take a needle roller, and then fitted to the tensioner assembly arm, as Kawboy suggested ? I might order one and try it, assuming I can find out the dimensions - which seems difficult.    

   www.cmsnl.com/products/roller-cam-chain-...IMN9w1IaAnZQEALw_wcB

Jim:  I'm going to order one of those and take it and a J78 bearing to a machine shop.  Relative to the overall steel hub dimensions - that's a fair bit of material to remove !  If they have to start making torque-plates and/or other clamping devices the price may not be worth it, in which case  I will use one of the two I made, with confidence.
thanks

I'm puzzled by the fact that the J78 bearing is sized in IMPERIAL dimensions. Why is that?

With regard to the availability of the original type cam chain tensioner roller, I thought I would ask ZED Parts ( in England)  what they use when reconditioning engines. 
I also asked about the KZ900 / 1000 roller dimensions in the hope that it could serve as a substitute for the obsolete 1300 original.
Here I quote the response from the delightful Debbie:  

"Back in 2009 when these became obsolete, we had 50 made by a local company. Even back then it was £2.5k to have just 50 made because of tooling costs, the quality of the rubber that had to conform to specific standards for our insurance, and the 11mm bearing which is not standard size.
Despite trying our hardest to copy the original exactly and making it out of top quality material so it would not fail, customers complained about the price saying we were ripping them off when we were only barely covering our costs. When we ran out last year ( yes it took over 10 years to sell all 50 and make our money back), we enquired about having more made and the price had doubled. There is no way customers would pay what we would have had to charge so we declined.
We do not have any more now and this is one of the reasons we have stopped doing rebuilds. If we do find a second hand good one, we will let you know. They do come up in engine dismantles that we do sometimes.
I am sorry we cannot provide a more favourable reply. But this is what happens when you don't go to China for cheap inferior products and try to have them made locally using quality materials. We refuse to have products made that may fail and wreck these beautiful machines and our reputation.

We have had quite a few things made and try our best to keep things in supply. 
Although you may see £100 as reasonable, many said that the £80 we charged previously was far too much.
We have recently invested £3.5k in having gaskets made. Many of the originals are no longer available and in recent months, the pattern Athena ones started to become obsolete. We had original templates so had batches of 500 of most of them made at a factory in the Black Country near us in the heart of industry. The tooling cost for each item averaged £50-£60 but we know the quality and cut is good. 
The cost we are selling each at is a fraction of the original and even so we have had people moaning that the thickness is incorrect. We have actually measured the thickness and it is identical to the original. I think there are some, especially on forums, that just like to complain.

As I write, Oz is measuring a Z900 roller.......


He says the internal diameter of a Z900 roller fits a 13mm pin
The Z1300 one is an 11mm pin
The outer diameter of the Z900 roller is 50mm and the Z1300 is 36mm.
The width of the rubber on the Z900 roller is 11mm. The Z1300 roller width is 14mm
He is using an old Z1300 roller that is a template and a bit worn, so unfortunately it is not one we could sell you.

The Z900 roller is for a roller chain and the Z1300 is for a Hyvo chain.
We learnt a lot when visiting various factories to get quotes for the white nylon gear that is also obsolete! These quotes were also far too high for us to consider having them manufactured. And again we won't go to China."     End.


So I guess that using a KZ900 / 1000 roller, would not be wise due to it being narrower than the 1300 part.   I assume that the KZ900 / 1000 guide roller will also be 11mm, so again, that would not be ideal for use as a tensioner roller.

MCG / Z1300de  in Germany confirm that they do still have the original Kawasaki tensioner roller available. 

Finally, I will mention that I intend buying as many of my 1300 parts requirements from ZED Parts as possible, as they impressed me greatly with the speed and comprehensive nature of their response to my enquiry.  As a point of interest, two other internet sellers I tried have yet to respond after three days !  People like Debbie and OZ at ZED Parts deserve our support.