Cam Chain Tensioners - ZX11 tensioner as diagnostic tool

In the original FAQ David gave us an interesting way of estimating  wear on the cam chain, it's guides and tensioner. I've copied the following question and answer from the original FAQ I'll catch up with you below.
Q:  I recently purchased the new cam chain tensioner you recommended how ever I have a question; there is a arrow on the tensioner does this point up or down?
  A:  You want to install the tensioner with the arrow as close to "UP' as you can make it.  Thinking of the gas tank being North and the ground being South, the arrow will point to the northeast position when installed.
This is most important!!  When you put the ZX-11 tensioner in, count the number of clicks the plunger went down before it stopped.  The Cam Chain rides over a nylon idler gear on the back side and these gears tend to disintegrate with age. You can pull the valve cover and look at the gear, (good time to adjust the valves) or another way to tell is to pull the tensioner back out if you've already installed it, depress the plunger, reinstall it and slip a small allen wrench in the hole and depress the plunger slowly and count the number clicks till it stops.   
It should click 19 - 20 times total if you extend it while it's out of the bike.  If you put it in and it goes more than about 10 to 12 clicks and there's 19 total clicks it could go, then your gear or the tensioner sliders are worn too far and you need immediate repair.  Do not start the motor!  It should really only go down about 3 - 5 clicks or less if it's in excellent condition.  I put one in that had a new idler gear and it only depressed one click!
There's also a nitrile plain roller on the bottom side of the tensioner assembly that needs to be looked at.  You may need to put in a new gear and a roller.  Order these parts from Kawasaki.  The head has to come off to put these parts in!   Here again, Kawasaki gaskets are preferred although others are available.  Check the links page for aftermarket gaskets.
Kawasaki Part # 12048-1113 Tensioner Assy, Part # 11009-1858 Tensioner Gasket is the ZX-11 parts if you want to go this way, or there are other options mentioned in the tech articles.

Bill again:
I'd been working through the fuel injection then the cam chain tensioner then why not the valves. Can't seem to finish one before I'm off after something else that has inserted itself into my critical path. I had an interesting experience recently when fitting different tensioners to my ZN1300. I removed the ball race/hydraulic tensioner and it's supply tube. I just happened to have a tensioner from a ZX11 and it appeared to be unused. I use David's method and first found that before installation my ZX11 tensioner had twenty clicks in it from full retract to full extension. I installed it on the back of the block and then carefully pushed the plunger deeper into the block. I encountered the tensioner on my twelfth click. Not Great but probably a fair warning. I removed the valve cover and saw that the flats between the gullets of the cam chain toothed idler sprocket were down to about 2mm. The plain roller is Nitrile (rubber) and its purpose is to absorb the minor changes in the chain stretch to dampen out the vibration seen at the tensioner. Nitrile is very compatible running in hot oil to a limit and will slowly harden over time. The harder it gets, the more likely it is to crack and pieces will eventually start to break off. It's just as important to inspect the Nitrile Plain Roller as the nylon toothed roller for wear. (How is the nitrile roller accessed?) This ZN only has 23,000 miles on it. I haven't found any bits of plastic yet. I'll take a pic and post it tomorrow. I checked the service limit on the cam chain and found it to be fine.
My plan is to fit a manual APE tensioner as soon as it arrives from Pit Stop Performance. In the mean time, if David's suggestion to use a ZX11 tensioner as a tool is effective and it seems to be in my case. I can expect to still have 2/5 of the adjustment left. I'm going to button it up and get back into the fuel injection setup that I was working on previously.
I've been warned so more frequent checks on the cam chain tension are going to be in order. I'm on a waiting list for water pump shafts so I'll leave the R&R of the head to a later concurrence.
Thanks for reading !
Bill

 

I recently purchased and just received a zx11 tensioner from EBay. I also bought a 0-10 lb. weigh scale so I could properly measure the compression of the spring. Sometime this week I plan on measuring the spring compression of the zx11 tensioner and if I can locate the stock KZ13 tensioner, I'll measure its spring tension as well.

In addition to the toothed roller there is a plain nitrile roller that is just as important.  While it's more difficult to examine, the plain roller is Nitrile (rubber)  it's purpose is to absorb the minor changes in the chain stretch to dampen out the vibration seen at the tensioner. Nitrile is very compatible running in hot oil to a limit and will slowly harden over time. The harder it gets, the more likely it is to crack and pieces will eventually start to break off. It's just as important to inspect the Nitrile Plain Roller as the nylon toothed roller for wear. Now sourcing a replacement for the Nitrile Plain Roller is another issue.

As an alternative, a while back I bought a round bar of Delrin to machine up replacement rollers and install a new roller bearing in the Delrin roller. Delrin is a great machinable plastic with wear characteristics far greater than nylon but the cost of Delrin is about 10 times that of nylon and that cost is why most products are made of Nylon 66. Also, Nylon 66 is easily cast in a mold to really fine tolerances so no machining is required. If you've ever taken apart one of those cheap battery operated clock mechanisms, you've seen the tiny gears and you can imagine the price of the mechanism if they has to cut all those gears.

I'm rethinking the Delrin tension roller since the Delrin is hard and will not absorb any chain stretch, but now I'm stuck figuring out how to vulcanize Buna Nitrile to a roller bearing. Loctite used to make a cryanocrylate glue (superglue) for rubber called Black Max and I think its now called Black Prism. It might work although learning how to vulcanize the rubber would be the way to go if it can be done at home without fancy equipment.
I'm sure most people will not go out and buy a ZX11 tensioner just to use as a measuring tool so at some point another task will be to come up with a measurement that can be taken with a depth mic or vernier from the face of the cylinder block that the tensioner mounts to, to the back side of the tensioner arm, to determine an acceptable depth that the tensioning system can run at before teardown maintenance is required, so that's on my list to figure out as well.
I still think the zx11 tensioner is the Bee's Knees for the Ultimate Mod since the back bolt has lots of meat for drilling / tapping for a backup bolt that could also be removed and measured for depth engagement to determine tensioner wear. A simple 5 minute check that could be done at every oil change without taking parts off and replacing gaskets. The question to be answered is the change out of the spring to a lighter spring and that brings up another thought. The whole issue with the lighter spring comes into play when using the Nylon66 toothed tensioning sprocket. If one were to change out the Nylon toothed sprocket to the new Liska Steel Sprocket, I think the higher tension of the stock ZX11 tensioner spring would be just fine. (Throwing that out there for those interested in the engineering aspect of all this modification talk)