Cam Chain Tensioners

Hello Folks,
I'm interested in Kawasaki's 1300's reputation for undependable cam chain tensioners. I'd like to hear from a broader community about these supposed weak tensioners.
Question: Have you ever had a cam chain tensioner fail resulting in damage to the engine?
Question: Do you actually know someone who has experienced such a failure?
Question: Is this reputed failure limited to Kawasaki Sixes or do other brands and designs suffer from tensioner failures as well?
TIA
Bill

May be of limited relevance.

   Honda did a recall on the camchain tensioner of vertical twin 360's circa mid-70's due to outright catastrophic failures.  At around the same time, rocker arms were also subject to a recall. When a dealer performed the tensioner recall, two punch marks were to be struck above & below the dash in the motor ser.# to indicate the recall service/replacement had been done.

   There's lots of info on the interwebs about it. Below is an AI overview from a web search:
"Honda CB360 (and CL360 ) had a known issue with its cam chain tensioner in early models (around 1974-1975) leading to a factory recall for a redesigned, more durable tensioner and guide, indicated by two punch marks on the engine case near the VIN, but many bikes still need replacement as the issue persists with wear, requiring periodic inspection and adjustment or replacement with modern parts for reliability."

   The Lovely Z1BEBE's first bike / training wheels was an unrestored-original, one-owner creampuff 1976 CB360T we found late '80's with only 300+ mi. (!) on it, still shod with the now-dry-rotted OEM tires.  No punch marks were present, but the new tensioner was factory OEM by that time.  It ran fine for the 5,000+ mi. she rode it her first Ridin' season plus later, as we kept it for another ten yrs. or so to scoot around town on after she got her Z1-B.  We sold the 360 to make room for more Z1's.

Good Ridin'
slmjim & Z1BEBE

As I remember, Honda V4 750's in 1983 and 1984 had a recall where the dealers replaced the cam chains and tensioners because of early cam problems.  There were also theories that the cam problems were due to material quality issues in some cams and/or machining issues.  Those motors also had oil flow issues to the top ends.  I had a 1984 and when I bought it the PO bragged that "the cam tensioners have been done at the dealer in the recall".  Maybe someone can remember more?

As far as KZ's go, when I had the top end of my 900 motor apart last year I found some sprockets with the rubber separated from the bearing (see pic).  I think it was due to 45 year old parts not being run in 15 years.

I did not know what the 1300 tensioner looked like or operated. Pics from a FSM I have for them, it appears to be a ball race system.  I do not know of other machines having issues but issues were rather common with this type of tensioner on the 650 for sure.

 

sf4t7 wrote:

As I remember, Honda V4 750's in 1983 and 1984 had a recall where the dealers replaced the cam chains and tensioners because of early cam problems.  There were also theories that the cam problems were due to material quality issues in some cams and/or machining issues.  Those motors also had oil flow issues to the top ends.  I had a 1984 and when I bought it the PO bragged that "the cam tensioners have been done at the dealer in the recall".  Maybe someone can remember more?

As far as KZ's go, when I had the top end of my 900 motor apart last year I found some sprockets with the rubber separated from the bearing (see pic).  I think it was due to 45 year old parts not being run in 15 years.

 

I had cam chain tensioners fail in 82' on my 82' V45 Sabre. I put 150k miles on that bike before I sold it. The dealer denied any help. American Honda gave me the parts but the dealer made me pay for the labor. The soft cam problem hasn't got me but I have seen pitted cams on other V4's. The 84' Sabre 700S and the 84' Interceptor 1000 haven't had any problems.

ALL three mentioned camchain tensioners had their problems. Slmjim, the 360 along with the CB350F and 400F had that horseshoe tensioner that wrapped along underneath the crankshaft camchain sprocket and totally different then any Kawasaki. It's main issue was that maintenance of adjustment was rarely addressed plus accessibility to the adjustment was in a precarious spot. Sandwiched between front lower engine mounting plates and frame down tube. Not maintained lead to chewing-up of the "shoehorn", have done my share of them. The early Honda VF750 "tariff imposed" and VF500 had problems too. They in comparison to any Kawasaki, were quite complex with that double bank of sliders/springs and guides. Can't remember exactly the issue but perhaps, oiling? The V4 had an oiling issue because the camshafts were the last to get oil pressure from the pump. Oiled thru the transmission before any oil got to the top-end resulting in a lot of those with still running Magna/Sabres and Interceptors with In/Out clattering of valvetrains. Moving to the early KZ1300. YES, those early camchain tensioners with the "Lock Balls" or also called Retainer were a miserable design Kawasaki chose to use starting in 1979 on many KZ models. Intention was a "wedge" of Shaft/Balls and metal tapered sleeve pressed into the tensioner body. Was only supposed to move in a progressively outward location to keep tension on camchain. In reality the balls in retainer would start hammering away at shaft and tapered sleeve or pinch points. This oscillation, because they do, rendered the design short lived. The "later" 2 wedge design was a Much improved/needed upgrade.        

Looks like the KZP one has a habit of becoming loose after running too. 

Not sure in the case of the 1300 but many times manufacturers get a “bad rep” for issues arising from incorrect maintenance 

My 1981 750 has the dual wedge type tensioner, with the cap and spring, which makes install of the valve cover quite easy.  I don't race, so can't say I max stress the engine, but so far, no issues.  

I think some people like to complain about tensioners needlessly.  They move to a manual tensioner, then over tighten the chain.  It's a common tendency, which is one of the reasons, I suspect, that the OEM's moved to automatic tensioners.

wrote:

Not sure in the case of the 1300 but many times manufacturers get a “bad rep” for issues arising from incorrect maintenance 


 

One of the members over at the 1300 site recently expressed an opinion in support of the OEM tensioner. Frankly such an opinion ran so directly against what has become (at least in my mind) the accepted conventional wisdom that I had to take a closer look. Are these failures a real issue or has the internet just created another meme? I've done a bunch of digging even inquiring at other Kawasaki sites (you may have noticed). Don't have enough information yet. Truly, the poll will give the best perspective, if we can get 20 or so answers. It may be that perception is the truest view.
Bill
Wake up Bill !!! the poll is over at the 1300 site. so far there are eight respondents.

I'll be pulling the KZP back in to reclean the carbs. Last time I went through the tensioner and it became quiet again. This time I'll take a closer look at it. It is the double wedge type. 

There is the double wedge auto type on my 1983 KZ1000R.
I took it apart and cleaned it.
When reassembling it, the smaller wedge, which gets inserted last, is supposed to stick out 7.5 mm or so, I believe.
The smaller wedge went in much more than that, so I'm not trusting it.

I'm going to have another look at it, but have already bought a new APE manual tensioner, so will likely use it.