Nah, it was a Sharpie.

 

Yeah, but it was fine point Sharpie.

 

Let me put it this way, virually all models of the KZ in-line fours have failures, the Eliminators and the Concours along with comparable ZX Ninjas have failures, some ZX6s have failures (I think more go unnoticed though due to loud exhausts), the KLX650 has failures, the Suzuki DRz400/Kawasaki KLX400 has failures, the Suzuki GS in-line fours have failures, and Honda CBR600F series have failures. It is far from unique to the 250. I've only sold a few to the 300 riders, so I'm thinking they are either ignoring it or just replacing things as they think they need to, since the 300 and the 250 are near identical. I've even had a few KLR riders pick up tensioners.

Remember, a lot of people are telling others the same thing I heard and paid the price for listening to them. When I asked about the clicking and rattling of my KLX back in 1998-2000 the response was "All Kawasaki engines are noisy." I "drank the Kool Aid" and ended up going through two OEM tensioners and then getting to rebuild to replace cam chains (2 in the KLX). When I got the Zephyr I asked about the buzzing noise, knowing what it was and was given the same line "All Kawasaki engines are noisy." But this time I didn't bite. I rattled some cages and finally had a few answers. One guy showed me what he made with 1/4" steel, I did it with 1/2" aluminum and made extra to see if they'd sell. They did and I got the manufacturing down to where the price line can be held. Then I kept it there so more riders wouldn't have to blow the money I did on a rebuild. As some of you now know - Not all Kawasaki engines are noisy... after you fix the problem the right way.

I have stated the reason for the failure a few times fairly mechanically soundly. It is all about tolerance stacking in the parts assembly (machined parts have a plus/minus factor), the indexing adjustment of the OEM ratchet tensioner (locks in in incremental steps), and the fact that the cam drive does not wear in steps that match the ratchet, the wear is dynamic. When the wear puts the adjuster pawl on the tip of the ratchet tooth, bad things are going to happen when the cam drive snatches. If it is bad enough you get the wear on the teeth (that shows as a polishing of the teeth, not really noticable damage unless you know what you are looking for) and the cam chain rattle when the chain slaps back and forth. It starts out light, but will get worse.

This can happen on about any bike with a ratchet style tensioner, but not on every single one.

It seems that some can not wrap their minds around this mechanical issue.

The fact is there is a problem on some other semi-automatic tensioners like those used in the early KZs. They use a locking bolt and a spring loaded tensioner adjuster. To adjust tension the lock bolt is loosened and then locked back down after the tensioner moves in. Problem is if the movement is small enough or the ****** in the drive is firm enough the adjuster will be pushed back into the previous marking or just plain pushed back, but tight enough the adjuster spring won't push it forward. I not only reasoned this out from a Suzuki RM that I did, but I got it first hand from a mechanic who said they'd stone the parts smooth again and have them laying around to swap out. The thing is a locked down thru bolt like on the tensioners I make just plain can't be pushed back like that adjuster can.

Kaw also used ramps and ***** with springs to try to do a dynamic adjuster, but it didn't always work so hot either. They are in the older Ninja 250s and they fail too, but the Ninja has a worse problem yet. There is a little rocker in the mechanism that will bottom out against a case before the cam chain is ever worn out of spec. Not enough adjustment there. I've got some parts and trying to make a rocker adapter to lengthen the travel... whenever I get time again.

The fact is the manual thru bolt style tensioner is the most reliable set up and is used by a huge number of racers just for that reason. You don't need something to break during a race, especially tapped out in fifth or sixth. The thru bolt style tensioner is only exceeded in simplicity by a hammer.

 

Mark, it's somewhat amazing how much "jerking" actually exists in a cam chain drive. One would tend to think that it would be a smooth action, but I guess the tension and relaxing of the valve springs is fairly dramatic in operation.

 

But the fact you used a cocktail napkin negates the fine point sharpie points.



Seriously though, Mr. Krieger i would like to purchase one of your adjusters but i can't seem to navigate your website for the life of me tonight.

Email ? PM ? whats the best method to make this happen ? Also i don't suppose you make an adjuster for a 02 ZX6R ?

 

click on his forum name, then click send an email.

 

A friend and I were talking about servicing the cam belts on cars. He commented that it would shock most people to see how much the cam belt thrashes around under acceleration/deceleration of the engine. He said it's not surprising the belts have to be replaced at intervals. Cam chains are the same, thrashing around, but last a whole lot longer than belts.

 

First off, I take it you emailed me and I answered. If not, do email. In a nutshell, I use PayPal for the most part and ship by USPS flat rate priority.

You'd lose it if you knew how we actually did everything. It makes napkins and Sharpies sound like AutoCAD 3D and a CMM!

So here it is...

TNC emailed pictures and a data sheet with measurements that were needed. I had to scale the pictures on a known dimension, then work out dimensions and angles from the pictures. I actually never have had one of the OEM units in my hands. The real topper in this whole approach was the "dirty finger" rubbing done on a scrap of paper over the mount hole/bolt hole area to see what was there for gasket space and positioning.

TNC tried the first one out and found we hit the nail on the head quite directly. the only change to the original was switching from an acorn nut on the end of the adjuster bolt to an allen nut to facilitate adjustment, which was hard due to the proximity of the exhaust - it was stinking hot when trying to do the fine tuning. Fact is now I tell people the cold set is close enough, unless they want to get real **** about being accurate and having some salve for the burns.

I find it to be quite fun to work up the drawings for new parts. I've got a few projects on the back burners right now. I just need to get off dead center and start working on them again.

 

Success!

I got the Krieger manual tensioner in the mail today and got it installed OK.
I only did the initial tightening and not the 'fine tuning' yet.
What a big difference! First time I started it up the loud clacking was totally gone! I let it warm up for a few minutes and still no clacking and not even any ticking that I could hear at idle. Then I took it for a short ride, and when I got back I could barely hear a very faint ticking. I guess I will try the warmed up 'fine tuning' after a little while. But boy oh boy, what a giant improvement!
If you need one or even think so, I say you must get one, worth every penny.

 

THIS is what makes it so much fun and worth making the part...

When it does the job, that's just plain fun. The only thing better would be if I could be there to help do the work and see the look on a rider's face when they fire up the bike. I've had the opportunity a few times, it's like priceless.