I'll send you a PM too Mr. Krieger.

 

Since this thread is about the cam chain tensioner, I'll ask my question rather than start a new thread. I've got an '07 250S with 300 kit, and the usual mods (jet, air box, Muzzy exhaust, etc..). 7200 miles on it. I can hear what sounds like (based on other people's descriptions) the loose cam chain at around 5500-6000 rpm while riding. It's really tough to hear at speed with my helmet on though. I've revved it to that rpm range in neutral and don't hear it. So, what I'd like to know is, if my cam chain tensioner is failing, will I only hear the noise under load, or should I also hear it under no-load conditions?

 

I hear mine regardless of load. Always a clatter at 5.5-6k.

 

I used to hear mine around 5 to 6 k as well as on deceleration.

I recently talked to a klx owner and asked him if he had the 'cam chain noise'. He said no, but said he hears what he thinks is just front spocket noise. Turns out its his tensioner.
I pointed him to this forum. Ignorance is NOT bliss...it can be expensive in some cases.

 

From what I know, if it is the cam chain tensioner you will hear it on a free rev up that high. Get a mechanic's stethoscope or long handle screwdriver (put handle to ear) put the tip in the area of the cam chain tensioner and listen as reved. Proper functioning tensioner will have a sort of swish sound, bad will have a tapping or rattle sound. If you probe around you can hear the valves tick, the louder the more clearance. I can find the two loose (.001 out of spec) valves on my ZR550 Zephyr. The stethoscope is great for locating sources of noise in an engine and under $10 at Harbor Freight.

You may also be able to listen carefully when you ride, moving your head to right and left. Where is the sound the loudest?

If the noise is loudest on the right it is likely the tensioner. It should do it with or without load.

If equal side to side you may be hearing a bit of piston slap, the piston clicking over at TDC on the power stroke. Both my 250 and 650 have a bit of that noise under load. This usually happens under load, louder under heavy load. Key point it is NOT the same sound as detonation. Fact is Kawasaki has dealt with it twice before, once on the KZ1000 in the 70s and again on the Vulcan 1500 around 2000. The fix was relocating the wrist pin slightly off center, minimizing the click as the piston rocked over TDC. The rocking is not a big deal, causing no damage or premature wear. It is just a noise. Kaw did the change to minimize the noise on their street bikes when it appeared. I know, that is where my big bore piston for my 650 came from - parts from a 1500 that were pulled to put in the revised part. We knew it wasn't a big deal so both pistons ended up in KLX650s making them 678cc.

But the check with the stethoscope/screwdriver is more reliable.

Hope this helps a bit.

 

Thanks for the advice guys!
Klx678, I didn't think about using a stethoscope. I'm thinking now it may not be the CCT, since I don't hear it with no load, but I'm definitely going to take a closer listen.

 

Wouldn't you know it, as soon as i had my Krieger ordered my bikes auto tensioner finally jumped another click and seated well. Oh well, I will still continue with the install, i just get a preview of how quiet my engine will be consistently.

 

That's funny, I had mine apart and rest mine and it's quiet too. Like you I'm waiting for my tensioner to arrive. While I had it out I noticed it was polished from rattling. Teeth look great but non the less I'm going to install the manual tensioner anyway.

Stupid Murphy law!

 

I was kind of hesitant to ride it because i thought it might have caught a good tooth on a "kickback" of sorts under heavy accel/decel. I would hate for it to catch a good tooth and end up being too tight. I will be installing my krieger asap.

 

I doubt it would catch the next tooth on its own and be too tight, but who knows? Forcing an adjustment with the auto tensioner can result in a tight cam chain per Krieger.