I have recently bought a 98 mod zx6r, and the bike is great. But i have noticed a kind of rattling sound at about 4-5000 rpm, but this sound appear only occasionally. I think it is coming from the front left side of the engine. Some of my friends say that this is a normal sound from old ninjas, but it feels wrong to completely ignore this. Anyone experienced similar problems, or have any idea what this might be?thx

 

Rev the bike to a steady 5000-7000 rpm, won't hurt anything for a few seconds, while sitting still and off it. See where the noise actually is coming from.

Could be a rattle in the bodywork or tank caused by sensitivity to the vibration of certain RPM ranges. My side panels can rattle on the KLX.

The primary drive is between cylinder 1 & 2, could have primary rattle. No problem, don't worry about it.

Could be a loose drive chain hitting something - I had that with my 550 two weeks ago when I was coming back from Mid Ohio. I heard clicking off and on. It was hitting the sprocket cover tunnel for the shifter shaft. Proper chain adjustment followed.

I don't know if it can rattle while riding, but sometimes there are clutch basket issues I've read about on some Kawasakis, but that's on the right side.

If it's intermittent and in the center it could be the cam chain tensioner, about which I know a lot. Some of the tensioners work fine. It's a stacking of tolerances on manufactured parts and the mechanical function of the tensioner that can cause issues, so it doesn't happen on every single one. It can be intermittent. On the KLX singles it was a loud clatter. On the in-line four it was like a hornets nest under the tank. Sometimes the tensioner would work briefly and it would be quiet, but only rarely.

Don't believe noise is ever normal, find out what it is. I heard the same "Kawasaki engines are noisy on both the KLX650 group and the Zephyr Zone. I had to replace tensoners in my KLX twice, first at 5000 miles and second at 15,000 miles. The second one ruined the cam chains (2 in the KLX) at which point I went to a manual conversion. Believing those who said it was normal cost me over $400. As a moderator at the KLX650 group for the past several years I will let KLX owners know about the possibility of the problem, which is very common on them.

The Zephyr had a bad tensioner too at 12,500 miles and the improved version was similar to the KLX unit and yours. No way I was going to put one of those in the bike, I made a manual unit and five extra. Now I make and sell them for Kaws and make one that fits the ZX6.

To listen for the noise in an engine you can use a long handle screw driver or a mechanic's stethoscope. PM me if you find you need one. I'm about 1/2 the cost of others. I have dozens of users in the Concours, Eliminator, Zephyr, and KLX groups having sent about 150 world wide since April of last year. But I will also tell you if it ain't broke don't fix it. I know of Concours riders with over 100,000 miles on the stock tensioner and others running miles without incident. If it does go bad you have time to take care of it, it isn't catastrophic.

Hopefully it's just a drive chain tapping something.

 

Thanx. actually i the sound WAS from the right side, dunno why i wrote left side. After some googling, and your post, my conclusion is to renew the chain tensioner. Ill just have to wait for the Haynes repair manual to arrive in my mailbox. Hope it is a quick fix(-:

 

A manual one is totally non-invasive, quick and easy to live with.

 

agreed, the stock CCT's are not the greatest. Try this; roll the bike backwards in 2nd gear then pop the clutch. Do this a couple times. Sometimes the kawi auto adjusting CCT will finally adjust after that.

congrats on getting the manual.

 

With the engine off

 

hahahaha, always a technicality! lol sheesh

 

Agreed on the tensioner.