Updated Camshaft Tensioner

Hello,

I got an automatic cam chain tensioner for a 1979 KZ, to replace the one on my bike. My '74 actually has a '77 engine 😂
My tensioner on the bike, after so many years ended up with the 10mm lock bolt (with locknut) starting to strip the aluminum housing's threads of the tensioner 😕
So now that I received the later model automatic tensioner, and seeing that it's different(and improved)-it does not have a lock nut like the original tensioner, though it looks quite a bit like the original-the lock nut instead goes all the way in, and has a washer-

I spent a few minutes disassembling it out of curiosity and since it's late at night, I'm not removing the old one until tomorrow or the next day-what an ingenious system, and I would not have figured out the procedure for retracting the tensioner rod if I didn't have the 1979 Shop Manual with Supplement 245 page showing the procedure:



The inner spring is like a gun, and the collar with ball bearings keeps it from retracting, unless a wire is used to hold the soft outer spring 😏
So now I have the task of removing my old one, with the timing mark ligned up, as per the instructions-
But, since some bikes probably still had the original tensioner with lock bolt and lock nut, the instructions at the beginning of the book are for the original tensioner, not the later model like I just got, shown on Supplement page 245(posted above)

The instructions, as I have always followed, and then the instructions from my other manual, the Z1 900-
But none of the manuals have enough details on how to remove the tensioner.  I plan on s
lining up the T mark, keeping the old lock bolt and locknut as is, and removing the assembly to install the new updated one I just got-hopefully the lock bolt with nut, even though the threads are stripping, still holds things together as I remove the assembly 😅

Any extra tips on what to do much appreciated-the improved replacement tensioner is ready to go, I fully retracted it with the little wire, but I did a test and when loosening the temporary longer 10mm long bolt(as per instructions) the thing shoots like a gun!  So when I mount it on the engine and loosen the lock nut it will indeed shoot into the engine like a gun after I mount it in place-

There is a section on the '79 manual on disassembling the engine, and it just says to remove the 2 bolts and pull out the chain tensioner, not much more detailed-
I'll read some more through both manuals before I start, but as mentioned any tips appreciated.  I've owned a KH 400 since I was a teenager,  4 H2 triples(still have my '74 I got in 1996) so I know triples and can work on them blind folded-

Long post, but I did spend hours searching about these tensioners, the manual APE ones, pros and cons, and settled on the one I got

Best regards,
JB

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But here's the Z1 900 Factory Workshop book procedure to periodically adjust the original tensioner, as many of us have known:
 


So since the updated tensioner is a supplement on the end of the 1979 manual, as mentioned in the beginning to the manual, the adjustment for some KZs was the same procedure as the Z1 900.  Once bikes started being delivered with this new one, the procedure is to install with pushrod retracted, loosen the bolt so it pushes in, and that's it(?) It will always be putting tension and taking up chain slack, since this system does not allow the rod to move back, so no need for a locknut.  The 10mm bolt is tightened with washer all the way in, and it constantly takes up slack(as I understand it)

Thnx
JB

Good information.  I'm currently swapping heads on my Z1 and now thinking about the tensioner too.

Just to add more to this info.

I removed the old tensioner after aligning the T mark, my worry was that since the locking bolt was barely doing its job since the threads were stopped, there would be a problem.  But it came out just fine-
Another note-the automatic tensioner's housing is slightly different, and uses longer 10 mm mounting bolts. Mine came with them.
Once the tensioner was mounted, with plunger retracted all the way, and after removing the wire holding the soft spring, the plunger mad a sound as it was released and pushed by the heavy spring.  Then the 10mm bolt gets tightened but it's job is done, no more loosening a locknut, spinning the engine etc to take up slack, it's done constantly 👍

 

 

You can modify your stock "automatic" cam chain tensioner to a manual cam chain tentioner.
The spring in the stock cam chain tensioner is to weak to set the chain slack right.
I do modify the manual cam chain tensioner, works perfect for me.
You can adjust the tension perfect on a idle runnig engine with the force of your finger tips only.

 

Not to discourage Your use of the 79-80 camchain tensioner assy but those were addled with problems. The only thing that keeps the pusher in place is that ball bearing retainer. Theory is the multi balls in the cage are on a "ramp" outer housing, kinda like a sprague clutch. What happens in reality is the constant vibration loosens up this assembly, that's why they were often replaced in many machines. The one you pulled is correct for your Z1 but..they had another style with the beefier/taller mounting boss. They were still manual but used on the 1977-78 KZ1000, that's a common sense barely noticeable "up-grade" and what my personal preference is. 

Whoops, just noticed. That's what Scirocco is showing you, just modified a bit.

Those tensioner in question used in 1979-up for a few years on the KZ650, kz1000 and others, automatic vs manual used up through 1978. The older ones, all you do is release the long 6mm bolt on the side of the tensioner to enable spring pressure to take up slack. Tighten the bolt and lock nut and you're done. The 1979-up with the flush mount 6mm bolt, all automatic, no need to do anything, but must be manually recessed if allowed to extend during valve clearance checks ect.
This all sounds like there is good advantages to possible upgrade to the automatic used in 1979 vs the old. Don't do it. The automatic used in 1979-up has about 1/2 the capability to extend vs the old one. Probably doesn't matter if you don't ride, but if you put on much mileage the newer one will max out in adjustment long before the old one.

Retracting the plunger was not easy, the inner spring was very stiff-everything wears out sooner or later, hence maintenance-
Happy with the new tensioner, could have bought a manual one too but decided on this one

JB

It may have already been mentioned, but after you retract and get the tensioner mounted and released, all you have to do when you want to lock it is remove the short 6mm bolt from the side and replace it temporarily with a long 6mm bolt like the old tensioner used. The longer bolt keeps the spring from extending when you don't want it to.
Another option is Helicoil on the old tensioner to repair the stripped threads which works and is easy. The old one lasts forever with no worries.

 
I did the same