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Discussion Starter #1
Working on an old (vintage) 1990 ZR550 Kawasaki and would like to make sure the cam chain is properly tensioned, since it has 63K on the odometer.
Reading the Service Manual is a bit scary, with two big caution notes regarding the ‘point-of-no-return’.
Anyone have any advice how to go about this procedure without wrecking things?
Any info will be greatly appreciated. Thanks!
 

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Buy a APE manual cam chain adjuster. Just bought one for my 79 kz1000 st shaft. Go on YouTube and most adjust them while it is running until the noise goes away. EZY PEZY!!!! But always check measurement on chain limit to make sure. Which is specified in your shop manual.
 

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There is nothing to tension, if it still has the stock tensioner. It is an automatic tensioner taking up the slack by itself, unless you have removed it, then there is a procedure of locking and unlocking it as you install the bolts.

The manual warnings are more far more scary than what you can damage, once you understand how it works.

If it is a after market manual tensioner, then is different; you have to rotate the crankshaft adjust in it, but you don't say what you have.
 

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Discussion Starter #4
I think the one I have is not controlled by the oil pressure......just a manual adjustment. Does the motor need to be running while I make the adjustment (its under the carbs which I have removed.)
What do you mean by "...you have to rotate the crankshaft adjust in it,....."?
 

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Do whatever the Kawasaki service manual says. The stock tensioner is probably an automatic tensioner that automatically takes up the slack as the cam chain stretches. Typically, an auto tensioner pushrod will only move in one direction, so if you have the valve cover off & rotate the crankshaft manually using a 17mm wrench, the tensioner will take up the slack created by rotating the crankshaft. Then when you re-install the valve cover, the cam chain will be too tight & you could damage or overly stretch the cam chain or maybe ruin one or more of the rubber slipper guides that the cam chain rides against.

Tensioner bolts. There is a warning that says do not loosen then retighten the tensioner body bolts. If you loosen them, the spring inside the auto tensioner will move the pushrod forwards; the pushrod only moves forward but not backwards; then when you retighten the bolts, the pushrod will push excessively against the cam chain. Never loosen the tensioner mounting bolts >> remove them completely; then re-install the tensioner as per the service manual. You have to follow the instructions >> you can't just remove the tensioner & re-install it.

ps: the KZ/ZR cam chain tensioners aren't controlled by oil pressure. Instead, the auto tensioners work by spring pressure & the pushrod only moves in one directions, ie, towards the cam chain.
...
 

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Yes,....what Martin-csr says. The "rotate crankshaft and adjust" is for manual tensioner. I think you need to determine if your tensioner is stock, or an after market manual one. It should be easy, just by looking at it.
 

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To me, it looks stock, although smoother than I remember from pictures. I do not have a 550, have a 750 which is totally different. But the after market manual tensioners would have a long screw sticking out the center for taking up the slack, and a locking nut.

The bolt cap you see in the middle is supposed to be a only a cap. If removed, it would allow a bladed screw driver to release the tension inside for removing, or installing the tensioner.

...thus unless a 550 owner pitches in, this is a stock tensioner as picture supports, and it is automatic and there is nothing to adjust....and unless there is a malfunction, what makes think you need to adjust the camchain tension????
 

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Discussion Starter #9
Hugojose: Thanks for the reply.
The reason I feel it might need adjusting is the fact it has 63K miles on it...plus I think I can hear a chain rattle while the engine is running...maybe not.
I did not realize it had a spring loaded automatic tensenor.
So, at this point the more relevant question might be: How can I tell if it is tight enough to operate, or does it need to be replaced? I do not want to jam up the engine just because I did not turn a screw.
Any ideas?
Thanks for your help!
 

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These engines are a little rattly, specially when cold. In general air cooled engines don't have liquid jacket to muffle internal noises. Additionally, they have a short chain primary drive at the bottom, which is not tensioned.

……..With an automatic tensioner, you can only remove it and inspect it, making sure moves freely and springs. The service manual only tells you, once you start removing it, go all the way. Don't go 1/2 way and then try to tighten it back. It will tell you also, have ready a new o-ring, and gasket. If doing it, follow the Service Manual procedure.

…..automatic tensioners, in general, move forward with spring and plunger, and then have a device preventing them from moving backward.


…...many people would also tell you to switch to a manual one as it is much simpler, but you have to adjust it yourself initially, then it hardly needs any adjustmemts…...with this many kilometers, you might consider also checking valve clearances.
 

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Discussion Starter #12 (Edited)
Hugojose/davidr1963: Thanks for your great input. It really helps.
I do intend to check the valve clearances. Is there a way to also evaluate the cam chain for ware and tightness while I have the top covers off?
Thanks!
 

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I believe the Kawasaki service manual would say 20-links should be between 127 and 127.4 mm. Service limit at 128 mm. Again, I have the 750, and the 550 is very similar, but unless something was abused real bad, even at 64k km, I would not worry too much about. this is to say, unless the cam chain tensioner runs out of play, there should not be any problem....

…...remember this, cars have the engine way out there in front, and most of them (OHC or DOHC) have rubber belts, not chain, thus sound very quiet. This is an DOHC air cooled engine between your legs with a metal cam chain...….actually three, with the primary drive, and final drive.

…..checking valve clearances, or worse, adjusting clearance, have some tricks. This is a shims under bucket design, and it takes removal of cam shafts to adjust....if you get into that, ask for tips. In those days Kawi asked for valve clearance check every 6K miles (8K km), very exaggerate, but still after all those km, I'd rather check.
 
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