Z1OwnersClub GB

Hi my 1977 Z1000 came with 2 cam chain tensioners, neither fitted but which is the correct one ?

The top one is from a Mk2 and better than the bottom one at not backing off. Put longer bolts in it though.

CJ, fit a billet item (APE) they're only £40 and well worth it
Debbens do 'em or Z1Ent...

The bottom one looks like the one from my Z1000A1 and seems to work fine.

Bet your missus will give you hell for putting oily bike bits on the bed spread

vduk wrote:The bottom one looks like the one from my Z1000A1 and seems to work fine.

Bet your missus will give you hell for putting oily bike bits on the bed spread

I have too agree with you vduk. The bottom one looks like the one on my z1000A1.

The other point I would make is that the spring on the top one is much lighter and on the basis we know the bottom is the correct fitment for your bike I wouldn't be inclined to use the top one.

top one (Mk2) only needs a light spring as it has sliding tapers so can't back off like the earlier ones.

having said that they can stick/jam ..........

chrisu wrote:top one (Mk2) only needs a light spring as it has sliding tapers so can't back off like the earlier ones.

having said that they can stick/jam ..........

So why does it still have a lock screw ??
I would say they're both manual and both require 'locking' after adjustment.... or am I missing something.?
The bottom one is the same as my Z1000 and as long as it's locked after adjustment there's no advantage over a billet item.

The sliding taper type were fitted to the Z500/550 for sure, and they were totally crap.

will,

the lock screw is to hold it in while you assemble the thing. after thats its not used.

A billet one is BEST, no doubt, coz once set, it CANNOT move.
I would rather spend £40 on one than a few hundred on a top end rebuild
Looks much better too

chrisu wrote:will,

the lock screw is to hold it in while you assemble the thing. after thats its not used.

Hmmm. That's what I thought until I released the screw and upon turning over by hand, the chain tension simply pushed the tensioner in, thus buggering the cam timing.
Surely there's no problem in keeping it pinched up is there.? Is that not how a manual 'billet' type acts ?

there should be a lock ring with ball bearing in it to stop it sliding back - sounds like thats missing.

In any event best go with your original plan........

The billet ones are just a big bolt, so its done up to the correct tension & a nut is used to lock it in position... simple & fool proof

The Mk2 works on a ball and ramp method, the ballrace is held in a taper in the outside casing and the rod of the tensioner pushes back against it locking the rod up as the balls go down the taper. I have lumpy cams and heavy duty springs and found that when being enthusiastic with the throttle it did back off, but not with std springs.
If you are turning it over by hand and it backs off moving the cam timing there is something wrong. Even with no tensioner in you should not alter the timing turning the engine over by hand, remember that you should always rotate forwards so that the tensioner side is where the slack is generated

The stock tensioner can and has on many engines backed off, ussually when the throttle is snapped shut at high rpm, the cam timing will then be wrong and the end result is the engine could drop a valve. Fitting a billet manual type is a must on any tuned engine and a good route to improved reliabilty on a stock engine. I have seen the cast alloy bodies break but normally the tapered push rod just gets forced back, the 6mm screw trys to purchase on the taper sideways, and being taped into a thin casting is not a good design. The standard tensioner gives you no finese in adjusting the chain either, if you unload the spring onto the camchain you are putting tension onto the camchain, the camchain is plenty strong enough but the camchain guide wheels and cam chain guide at the front of the block can wear premarturely, especially if the camchain is old and has not stretched evenly. It is very common to find the little camchain guide foot located in the front lower part of the cylinder block to have broken when we strip engines. I have binned more std tensoiners than I care to remember, it is just not worth taking the risk with a customers engine. Regards, Steve