OK All You 650 Experts Out There....

I need a little identification help here.

Is this the mysterious and elusive "manual" cam chain tensioner from a '77 engine ?? It was removed from an engine we were scrapping and it sure as heck is different from the one on my '78 engine. If it IS the "manual" tensioner, would it be a good idea to bin my "automatic" ball-race type tensioner form my '78 and put this on instead ??
Any thoughts/comments out there ?? Anyone ??

looks just like the one on my 78' i just went and looked,but my bike was built in august of 77' though.

It looks like the manual tensioner on my '77 KZ650C1. I've never had a problem with mine and I'm the original owner (45k miles). I have no experience with the automatic type, so I can't say if the manual is better or worse. Ed

I thought the 79 and up had the automatic tensioner, 78 and below was manual. It looks like the one on my '78 except the screw on mine is a bit longer and has a locknut on it.

Yup, it is a 1977 manual cam chain adjuster. I replaced mine with an APE adjuster and haven't looked back since.

My factory adjuster was acting up. The pushrod wasn't fully extending due to a the rod having a little groove in it from overtightening. The spring was also on its last legs. To top things off, I cracked the housing when installing it. Onto the junk pile it went.

Now, I must also ad that my lower cam chain sprocket and idler wheel was swapped out for a 900/1000 model as the 650 model was discontinued. The 900/1000 model is 5 mm smaller in diameter and becuase of this, the pushrod had to extend a little further.

I tried the old trick of drilling a hole in the back of the adjuster and threading it in to push the rod a little further to account for the smaller diameter sprocket but wasn't comfortable relying on this modification.

No problems with the APE adjuster and it is a set it and forget it upgrade, plus it looks pretty trick.

Cheers-Colin Firth-Ontario Canada

It's a 1977 or 78 KZ650 or KZ1000, or a KZ900 or a Z1 from 1973-1975. Nothing elusive about it as it was used on thousands of Kawasakis of these models and a very reliable piece. No difference in the 77 or 78 KZ650 tensioner, they both used the exact same manual tensioner. As mentioned the bolt has been changed, it should have a longer 6mm bolt with a lock nut to secure it. Nothing wrong with the automatic tensioner used on the 79s either in my book.

That is for sure from a 77 KZ650 as I took mine off too. Your's is an automatic tensioner however and I highly suggest replacing it with a manual cam chain tensioner from z1enterprises.com

I think there is a difference in opinion on what is a manual and what is an automatic tensioner.

I was led to believe that the '77 was called a manual tensioner with a pushrod that was released through a locking bolt that when backed out released the rod to extend inward, applying the necessary tension on the chain. The lock nut kept the bolt in the correct position on the pushrod preventing the rod from being pushed back.

BTW, Ron is correct in saying that the early model cam chain adjuster was universal for many of the early and mid-70's Kz bikes.

Cheers-Colin Firth -Ontario Canada

There has always been some confusion on what a manual tensioner is.
Manual: Used on 1973-1975 Z1, 1976 KZ900 and 1977-78 KZ650 and 1000. Uses a longer 6mm bolt with a jam nut. Simply loosen the jam-nut, loosen the long 6mm bolt and spring pressure tensions the chain. Tighten the bolt, tighten the locknut and you're done.
Auto: Used on 1979-80 KZ1000 and KZ650 and others.
Uses a 6mm bolt tightened flush with the body of the tensioner. Has a design that allows spring pressure to always be pushing in on the chain, but cannot move backwards. Fully automatic operation.
The main drawback to the automatic type is the available adjustment range is much less than the manual type. It will fail to tension a worn chain long before the manual type. Either work just fine on a camchain that is in good condition.

My take on it is this,...the tensioner pictured above is what I myself would call an automatic. Yes u have to open the nut and let it tighten itself more every once in a while but I call it an automatic due to it doesnt give constant pressure and the spring gives and takes depending on rpm's. I may be wrong, and it wouldnt be the first. I consider the MANUAL tensioner as like the one sold at Z1 that is basically a long bolt that holds a constant tension on the chain and does NOT give whatsoever no matter how hard u ride.

You are wrong. The tensionser shown is MANUAL. It DOES give constant pressure and the spring DOES NOT give and takes depending on rpm's. The way it works is you turn the crankshaft to a specific position and loosen the pinch bolt. The spring then pushes the tensioner against the cam chain. You then tighten the pinch bolt and the tensioner cannot and will not move. Ed

650ed is right. I had an automatic on my 1980 LTD. It has 3 balls in a part that goes into the front of the tensioner, and the shaft comes through and is supposed to allow only outward movement, but the balls were wore out and it allowed the shaft to move in also, making the chain loose and noisy. The bolt on the side is a guide to keep the shaft from turning and doesn't lock the shaft from movement. I replaced mine with the newer type double wedge tensioner from an 81 or 82. It works great, and it can't move inward. The 79 and 80 auto tensioners are junk and should be tossed out. Bob