I remembered that scotch and kept that in the back of my mind. It's an easy thing to still add. The one thing that was concerning me was how to keep the nut from spinning? A tight fit, that might prevent it from spinning.. A bit of red permanent Locktite?

How did you prevent the nut from spinning inside? Unless it's pressed very tight it might just spin along the added bold, back and forth with the vibrations, as it would be a loose nut in there (no pun intended), basically a threaded cylinder free to spin with the oil everywhere.

I also have those aluminum e-z welding rods, which are basically brazing rods. The results seem to be very strong, and people very happy. I've been considering building up that back of the tensioner.

I'll see what I will do, but with a self locking nut I think it will hold up. Definitely not to apply 29 lbs-ft! After all, thin aluminum brackets are often threaded and they work well, with just 3 threads cut. This bolt needs just enough tension to keep it in place, no extra mechanical forces affecting it. Except in case of the tensioner failure and backing off - that added internal nut would prevent it popping out if threads get stripped. But would there be that much force from the spring? I don't think so.. And if the nut happens to be right at the end of the bolt, the bolt theoretically could travel far enough to let the chain jump. That would need to be measured to confirm or dismiss.

Well, I have one more tensioner to play around. I will try the e-z aluminum weld and see if this can be done.

I did the same Mod. with my OEM tensioner BUT:
There have been concerns regarding this mod - specifically - regarding the lack of material in the end, itself. You only get, at best, a couple of threads !
I solved that concern by supplementing with an internal nut.
www.kz1300.com/index.php/forum/engines/3...pgrade?start=6#23340

The thing that's always bothered me about the manual tensioner option, or even swapping in the tensioner from a Zxxx..(can't remember) is that there's no way to know, at least for the average Joe, when the tension is correctly set

Exactly. I played with mine and turning it by hand couldn't feel anything - it's is just too stiff. Then adjusted it looking at the chain and feeling the tension by hand. After running the engine played with it a little more back and forth, and left it where I thought it sounds the smoothest. All looked fine when I removed the cover after a few hundred miles to check the valves. Now it's time to do the same. I'm going to do the same mod on my spare tensioner for the spare engine I am building. I think having the correct as per design pressure there is the best - no guessing. And with this mod, it preserves the automatic adjustment and is also safe.

I've decided to revisit the cam chain tensioner. Right now I have a manual one installed and it's been fine. But after reading a lot of from people who are using the stock tensioner modified, I decided to do this modification as an exercise.

First, I carefully checked where the center of the back side of the housing is. Very easy, putting it on the table and giving it a spin. Like a spinning top.
Marked the center, and carefully drilled there a pinhole. Followed by larger drill bits, until the last one - 5 mm. Then cut a 6 mm thread and voila, it's ready. All freehand style

I decided to use a brass washer to protect the aluminum body of the tensioner, and also to use a self locking nut.



Before assembly. The pre-loaded spring is held with a nail.



The tensioner's push rod is held in place by a bolt. 0nce installed on the bike (with a thin paper gasket), I will release it and let it do it's job. Then - I will replace it with the original stopper bolt and screw the added limiter bolt in, securing it with the self-locking washer. The stopper bolt is not tight and has nothing to do with applying tension, so it will be very easy and accurate to screw in with fingers. I will back it off slightly on contact, maximum 1/4 - 1/2 turn.

So, the plan is to remove the manual tensioner and replace it with this modified Kawasaki stock. I will do it with the cam cover off, when also checking the valve clearances. I'd like to see how far it goes comparing to how I adjusted the manual one. After some more polishing that is!

Another thing to do will be to mark the different positions of the stopper bolt - all the way out, in, and the current position for reference. I will also measure it with calipers and keep track of the applied adjustment.

Hmpf,

I just did a little more research and it seems the compression test results I have are pants.

I can't actually find the official specs for cylinder compression for these bikes anywhere, but from most of the conversations on the forum it seems I need 120-170... almost double of what I have.

At a loss as what to do now.

I do not have a leak-down tester and after having done it three times now, I am pretty sure I got the timing right. Could it be that the cam chain is worn - despite me measuring it and it being within spec? The cam chain tensioner seems to be right on the limit, as in: when I put it in and push the spring in, there are more than 10 clicks before it stops (this is the modified ZX10 version)

Paul

Just getting back from the Panama after a couple of weeks away.

Sounds like a cam chain noise to me, Almost as if the tensioner is too tight and the cam chain is riding hard on the nylon sprocket. I would be pulling the cam cover and having a good look around. and don't rule out the possibility of a bad needle bearing on the nylon gear. Definitely cam chain related noise.

You should hear a whine of a timing belt when they are tensioned up too tight.

Hi Scotch and thanks.
Let me see now… prior to initially starting the engine, I checked that the cam timing (was as per the manual), and that the manual tensioner was doing its job (was finger tight).
I checked the valve adjustment and changed out 4 shims (of the clearances requiring change, none was tighter than 1 thou clearance).

Removed the oil pan and checked the oil pump pick up screen for debris (was clear).
Measured the primary and secondary chains while I was there…

Removed the air valve reeds and replaced with OEM blanking plates, gaskets and covers (because every hose end was split).
I removed the LH & RH engine covers (and stator) for re-polish.
I removed the starter motor, checked, cleaned and reassembled.

New oil filter/ oil, spark plugs and that’s about it…

I did have major issues with the carbs both before and after the first start and then road test.
Whilst looking for answers, I checked that the auto advance unit was lubricated and advancing properly (it was).
The noise was first noticed during the first road test (after about 4 miles), but it was (and is) difficult to pin point – in time I was able to discount other possible causes, like front brake, tire or cooling fan – it does sound like it is coming from the front (top) of the engine?
Andy

Ha, I finally got my A1 out on the road and have been working my way through the usual problems...
It is running sweetly now on all 6 and pulls like a train, only problem is I have this unidentified engine noise - maybe the cam chain or water pump??
I have had a good look under the cam cover and the cam chain is not loose (manual tensioner is finger tight), the plastic idler wheel looks ok, had the manual tensioner out and the black rubber roller seems to be present.
Before I start a major disassembly, has anyone come across this before????
Cheers
Andy
Here is the you tube link

razmo99 wrote: Correct me me if I am wrong but the original concern with the OEM tensioner is that it will back out and the chain will slack?

With the Kz I got the PO simply but a bolt and nut on the end. You just wind it in till it lightly touches and job done. Just adjusted it every now and then, and no worries about too much or not enough pressure on the cam chain.

That's exactly what I was suggesting....

Bucko wrote: Made me think: why not drill and tap a hole for a small bolt (and lock-nut) in the end of the tensioner body (axially lined up with the tensioner plunger). Retain all the internal tensioner parts and just lightly snug up the bolt occasionally to take up any slack left by the tensioner adjusting forward. i.e preventing the plunger from moving backwards.

Correct me me if I am wrong but the original concern with the OEM tensioner is that it will back out and the chain will slack?

With the Kz I got the PO simply but a bolt and nut on the end. You just wind it in till it lightly touches and job done. Just adjusted it every now and then, and no worries about too much or not enough pressure on the cam chain.

Ah yes, scotch, I now remember your post about fitting a nut into the tensioner. Thanks for reminding us.

I was also concerned about the lack of material in the end of the adjuster body. I used an appropriate nut, rounded it, chamfered one side to fit correctly in the bottom of the stem and when correctly sized, pressed it in.
Note: The addition of this internal nut changes the relationship of the notch in the adjuster and the short bolt that locks the assembly in the retracted position for assembly. You will need to use a longer bolt to hold the assembly fully retracted. When the CCT is installed, replace this (longer) bolt with the OEM.

I actually have exactly those two modifications made, the longer bolt on the tensioner with locknut and another bolt threaded to the end of the body. The latter serves as an indicator for the stretching of the cam chain and also indicates the condition of the rubber roller at the bottom of the tensioner.
That is how I found out recently that the rubber was gone. Found it later at the bottom of the oil pan...

Bucko - tapping the tensioner body at the end has been discussed previously, but the opinion is that the metal is very thin at that point, so you would not have much of a threaded area. However, the tensioner locking set screw at the side screws into a cast in boss, so has ample threaded thickness. A lock nut would be a wise addition in conjunction with the longer locking set screw.

Phil wrote: Lauri Nurminen quoted:
"I use the original tensioner, just change the M6 bolt for one 15mm longer. Every 2000 km or so I loosen the bolt, let the adjuster do its thing and then lock it with the longer bolt. The tensioner can not fail when locked in place. Costs only what longer bolt costs."

Just thinking out loud about this....

The threads in the body of that tension wouldn't take much torq to strip out. This exact thing happens with CB750/900/1100F B chain tensioners which have just such a bolt - kind of painful to fix as the tensioner body is cast as part of the cylinder head.

Made me think: why not drill and tap a hole for a small bolt (and lock-nut) in the end of the tensioner body (axially lined up with the tensioner plunger). Retain all the internal tensioner parts and just lightly snug up the bolt occasionally to take up any slack left by the tensioner adjusting forward. i.e preventing the plunger from moving backwards.

I personally have been swayed by new information regarding shortening the ZZR CCT spring & whether it increases tension force, this was posted by Ian on the international Z1300 Facebook page after he carried out tests:
"well WoW the standard cct spring is putting 650 grams of force on the chain at a length of 52 mm
the zzr spring is putting over 1030 grams of force at the same compression with 10mm cut off, that was taken at the end of its travel which is 52mm so if you cam chain isnt that slack then more force will be applied.
compressing the ZZR CCT by 10mm nearly doubled the force applied to 2000 grams.
the standard CCT only went up to 920 grams at 10mm compression.
Phil i would be interested in how much force you will get with a full length spring.
think ill stick with the standard CCT with modified with a back stop."

Lauri Nurminen quoted:
"I use the original tensioner, just change the M6 bolt for one 15mm longer. Every 2000 km or so I loosen the bolt, let the adjuster do its thing and then lock it with the longer bolt. The tensioner can not fail when locked in place. Costs only what longer bolt costs."

Luckily I kept the original CCT when I changed out mine for a ZZR one 20 years ago, I think I'm going to do what Lauri has done

Many thanks Pete, that is the info I was after.

Best
Paul

The modification is to shorten the spring by 10mm.
Simply remove it from the tensioner body and cut 10mm off either end.
Next fit the body (with a new gasket) into the tensioner hole, then insert the spring with the chrome pin inside it and screw the HOLLOW Bolt with the copper washer fitted, into the end of the body and carefully tighten the bolt. Its a bit tricky as you have limited space available.
You will hear the tensioner clicking and pushing against the guide inside the tunnel as you tighten the bolt........thats ok !

I personally would not start any Z1300 engine with the original tensioner fitted, having had 2 fail over the past 40 years and paid the price of new valves, cylinder head etc...etc...etc....its the VERY FIRST MOD I have done on all my Z1300 and KZ1300.
Its a very good, cheap worthwhile modification and once done you can forget it as its all self adjusting.

Another good alternative is the way Jim has mentioned with a Manual Type Mod to the original tensioner or fit an APE Manual Tensioner...........the only slight drawback with that way is having to manually adjust the slack every now and then.

Pete Finn
UK

If you search the forum for cam chain tensioner you’ll find lots of information. Member strate6. - Pete - has used the ZX11 tensioner with , I believe, 10mm cut off the spring, and he has had no issues on his many 1300’s. Yet, the truth is that shortening the spring actually INCREASES the force needed to compress it ! So what effect on the cam chain gear / roller longevity will that have?
There are other options apart from using the ZX11 tensioner, and these have been discussed on the forum. Personally, I intend using the original tensioner, but with a locking bolt, as Lare Numinem suggested.

Hi all, I thought I'd give this query its own heading, seeing as it is so important.

My 1979 basket case still had the original cam chain tensioner and I was advised through the forum to upgrade that. Suggestions in the FAQ on the site pointed me to buy the ZX-11 one (Kawasaki Part # 12048-1113). However, there seemed to be a question about having to shorten the spring for the new one, but no real clarity anywhere that I could find.

The question was: can the new one simply be used or does it need the spring shortening to lessen the tension so it is the same as the old one? The thought being that the new one would put too much tension on the chain and wear out the chain rollers(?).

I was thinking of all sorts of clever ways to measure the different tensions, but in the end I simply compared the pressure I needed to used to depress the springs by one finger, and certainly the new one needed a LOT more pressure to depress fully. Therefore the tension will be much more with the new one.

So the questions still stands: Do I need to cut the spring on the new tensioner before I install it? What have other people done?

Pics of my test attached.

Both in the vice:

New one:

Old one: