Top Cam Idler

Where do you reckon these sprockets collapsed?..... Needle rollers or rubber mount?

Yeah! You don't need to be a Chicken Farmer to tell their mode of failure.
RegardZ.

$400 for new idlers? I think you are shopping the wrong places...

NEW billet idler sprockets under $80 each...
Genuine Kawasaki idler sprockets are $135 each

Garn wrote: Where do you reckon these sprockets collapsed?..... Needle rollers or rubber mount?

Yeah! You don't need to be a Chicken Farmer to tell their mode of failure.
RegardZ.

YIKES !!!!! :sick: :sick: :sick:

Jeff.Saunders wrote: $400 for new idlers? I think you are shopping the wrong places...

NEW billet idler sprockets under $80 each...
Genuine Kawasaki idler sprockets are $135 each

Yeah that was a boo-boo on my part. I have that number rolling around in my head for ALL the timing parts less the chain, and that was with the chain guide,new tensioner arm(which I will still be buying),rubber dampners,center lower stock rubber idler/guide,aftermarket(3) idlers, new top idler tower and solid top idler mounts( still haven't decided on those since I hear they are noisy but I like the fact that they last forever)so half of that stuff won't be needed....bear with me I'm still new to this.

Jeff.Saunders wrote: $400 for new idlers? I think you are shopping the wrong places...

NEW billet idler sprockets under $80 each...
Genuine Kawasaki idler sprockets are $135 each

By the time those liska idlers get over here they are £100 (160usd) each and the top idler or tensioner with the steel brackets are much more.
The genuine idlers are at least £130 IF you can find any which was one of the the initial reasons i turned to re-manufacturing the originals.
They screw us to death here with tax and vat it's almost worth moving to the US for all the money i'd save.
I was lucky to have some stuff sent over from Hoopers which they thankfully marked as a gift.
The Dyna ign worked out at £80 which even with shipping costs is nearly half the price of buying over here.

4TheKZ1000 wrote: Larry C Wrote: If you want to waste your time fk'ng around trying to make chicken soup out of chicken shit...

Larry made this comment about a picture with three KZ motors on a bench being worked on.....hey Larry....you calling KZ motors "chicken shit" It sure sounds and looks that way ??????? ( see above )

:whistle:



No. I'm saying that for what they cost, it's not worth the time and effort to go through all that crap to rebuild one. When I rebuild a motor, I toss the trash parts and install new parts. When you ship a motor out, there's enough worries over potential problems such as cam failures without adding to the misery by installing some rebuilt $100 sprocket.

I don't get involved with bubble gum and barbed wire projects.

As far as it goes Garn, what you see in what you're working on doesn't matter to me. If you don't see failed bearings in any of them, it's irrelevant to the ones I've seen with failed bearings. Most times it's the rubber worn out but the bearing will still work. I toss that shit in the trash.

Up till 79, the top sprocket was designed to have a replaceable bearing. In 79 they changed the design to a throw away type. Yes, those could be rebuilt but not as easily.

When a customer is handing you 3 or 4 thousand dollars to completely rebuild a motor, they expect new parts inside it. When I completely rebuild a stock motor, the only part of the cam chain system that gets reused is the cam sprockets. Do it once. Do it right.

That's not saying anything against Zed1015. I like that guy. He's pretty handy and clearly has a firm grasp on things. It's price driving his direction and I can understand that. I always take a look at whatever project he's got going. He's done some nice bikes.

When you set out to rebuild one of these engines, the first order of business is to come to terms with the fact that NOTHING about doing that makes any financial sense at all. It's something that people do because that's what they want.

LarryC wrote:

When a customer is handing you 3 or 4 thousand dollars to completely rebuild a motor, they expect new parts inside it. When I completely rebuild a stock motor, the only part of the cam chain system that gets reused is the cam sprockets. Do it once. Do it right.

That's not saying anything against Zed1015. I like that guy. He's pretty handy and clearly has a firm grasp on things. It's price driving his direction and I can understand that. I always take a look at whatever project he's got going. He's done some nice bikes.

When you set out to rebuild one of these engines, the first order of business is to come to terms with the fact that NOTHING about doing that makes any financial sense at all. It's something that people do because that's what they want.

You are fully 100% correct when it comes to business and when doing a customer bike i don't go to all the bother re,making them or any other parts when replacements are still available as it would end up costing even more when adding in the labour etc.
I do these for myself and they cost nothing but the new bearing.
Sometimes i may do a few for close friends etc on an exchange basis + cash but you couldn't compete with mass manufacture and certainly not make much of a profit.
To be honest it's not really price that drives me as such with my own projects,its more that i just like to do as much as i can with minumum outside help, there is usually no deadline and i hate junking a part if it can be safely brought back to reliable use.
If something i do helps someone with the relevent skills keep their bike on the road rather that abandon it then all is good but it won't be putting anyone out of business.

zed1015 wrote:

LarryC wrote:

When a customer is handing you 3 or 4 thousand dollars to completely rebuild a motor, they expect new parts inside it. When I completely rebuild a stock motor, the only part of the cam chain system that gets reused is the cam sprockets. Do it once. Do it right.

That's not saying anything against Zed1015. I like that guy. He's pretty handy and clearly has a firm grasp on things. It's price driving his direction and I can understand that. I always take a look at whatever project he's got going. He's done some nice bikes.

When you set out to rebuild one of these engines, the first order of business is to come to terms with the fact that NOTHING about doing that makes any financial sense at all. It's something that people do because that's what they want.

You are fully 100% correct when it comes to business and when doing a customer bike i don't go to all the bother re,making them or any other parts when replacements are still available as it would end up costing even more when adding in the labour etc.
I do these for myself and they cost nothing but the new bearing.
Sometimes i may do a few for close friends etc on an exchange basis + cash but you couldn't compete with mass manufacture and certainly not make much of a profit.
To be honest it's not really price that drives me as such with my own projects,its more that i just like to do as much as i can with minumum outside help, there is usually no deadline and i hate junking a part if it can be safely brought back to reliable use.
If something i do helps someone with the relevent skills keep their bike on the road rather that abandon it then all is good but it won't be putting anyone out of business.

Zed,

It's always a pleasure to read your posts. I wanted to be absolutely certain that there was no question that slamming what you were doing was NOT the intention.

Larry C

If I was building engines for a living and had my name and reputation attached to them then I would use new parts without a doubt. My situation is I sold a car that I liked very much to finance rebuilding my bike, I support 4 people on my income of 36 hours a week and I'm under the poverty level for the state of SC. So I thank zed with much enthusiasm for saving me money that I can give to Falicon or Pearson for my crank....I think most of the members here are in the same boat just some have more or less money to play with on their projects. This mod helps the people with less.

This whole discussion about the rubber between the bearing and the sprocket vs. using a solid metal sleeve makes me wonder why the rubber was used by Kawasaki. The top idler has damping rubbers between the upper idler bracket and the cylinder head, so damping between the bearing and sprocket shouldn’t have been needed. However, the earliest KZ650 lower idlers ran on shafts which were mounted metal against metal in the engine (see item 9 in 1st pic below). There was no damping between the shaft and engine so maybe the rubber in the sprocket was meant to provide some level of damping. If that was the purpose, I can see how Kawasaki would want to use the same idlers at all three positions. However, Kawasaki quickly changed the design of the lower idler shafts and cut a section out of each end of the shafts so they could insert rubber dampers between the shafts and the engine (see items 9 & 22 in 2nd pic). Now that the lower shafts also had damping I would have thought the rubber inside the sprockets would not be needed and the bearings could have been pressed directly into the idler sprockets. Maybe it was just more cost effective for Kawasaki to continue using the sprockets with the rubber rather than switching? Ed

650ed wrote: This whole discussion about the rubber between the bearing and the sprocket vs. using a solid metal sleeve makes me wonder why the rubber was used by Kawasaki. The top idler has damping rubbers between the upper idler bracket and the cylinder head, so damping between the bearing and sprocket shouldn’t have been needed. However, the earliest KZ650 lower idlers ran on shafts which were mounted metal against metal in the engine (see item 9 in 1st pic below). There was no damping between the shaft and engine so maybe the rubber in the sprocket was meant to provide some level of damping. If that was the purpose, I can see how Kawasaki would want to use the same idlers at all three positions. However, Kawasaki quickly changed the design of the lower idler shafts and cut a section out of each end of the shafts so they could insert rubber dampers between the shafts and the engine (see items 9 & 22 in 2nd pic). Now that the lower shafts also had damping I would have thought the rubber inside the sprockets would not be needed and the bearings could have been pressed directly into the idler sprockets. Maybe it was just more cost effective for Kawasaki to continue using the sprockets with the rubber rather than switching? Ed

They changed the design of the idler axles to prevent them from rotating in the barrel casting and causing excessive movemnent caused by wear.
The little rubber blocks are not there for damping but to prevent the shafts rotating AND are made of rubber only so they can "give" when the head is bolted on to allow for any slight variance in barrel deck height.
If they were solid they could prevent the head gasket from sealing in that area or allow the shaft to rattle depending on their height.
The idlers have rubber centers for the reasons i stated in an earlier post re- manurfactureing tolereances and audible noise etc.
If you pull some apart you will see that they are not perfectly identical and have varying degrees of runout.
The rubber centers compensate for this.

I thought they were there for damping since the parts catalogue calls them "DAMPER, guide sprocket." Ed