Metal Ringing Sound From Hero Honda CBZ's Engine.

Could it be a cell phone hidden in the seat?

Diagnosing a ringing sound by e-mail from around the world is not an exact science you are aware, right?

The best suggestion I can offer is to try to put a foot against the exhaust heat shield when the noise is present. Next guess would be the exhaust pipe/muffler. Lean a foot against that next. Any Thin sheet metal part might vibrate if not supported, or mounted loose. Try tapping any part of the bike you can reach and listening for the noise. Good luck. If needed we can send lynlynch there to help you look.

Click and Clack, the "Tappet Brothers," would surely know all about this. By searching under www.npr.com, you can probably find a number and call them up some fine Saturday during the "Car Talk" show.

Have a look in your toolkit. Try your mechanics toolkit. See if anything is missing. I know you are a tidy person and not a smuggler of rattly metal objects. But maybe, maybe....

You need not admit if this was the case. Good luck, Ky.

Some shaft seals such as at the drive sprocket shaft have metal shields or dust covers, one may have backe out and is spinning on the shaft and will give a metallic ringing with changing shaft speeds.

Good to have atleast some sensible answers!.. Thanks to John and our guest!.. I ll try sorting out the problem with the information i have received...

And KY.. the tool kit is well intact.. and no smuggling drama found.. i stand by my word! ;-)

bob and lynlynch.. thanks for ur funny answers... some fun is always good.. btw weather over here in India is not that bad at present.. u r Welcome here!

Have a great day (or night, if it's so)!

It sounds like you might be getting "pinging" or "knocking" since it only occurs under heavy load. Some possible fixes include using a higher octane fuel, or using a richer fuel/air mix. Another possibility is that you're getting preignition (pre-firing before normal spark ignition). This can be due to using a spark plug that is too "hot", or from carbon deposits on the head or piston. Either pinging or preignition causes internal shock waves (that you hear as a metallic pinging sound). If not fixed, either can damage or even destroy the engine.

It could also be a wrong spark plug, one that is physically too long and the piston is hitting it.....

When I first started to pollute this site, there was a problem with a Ford pick up that had a rattle at low engine speeds. After many guesses, it turned out that the dealership had dropped an exhaust bolt into the exhaust pipe when they had serviced the clutch.

I'm just saying, it could happen again.

He'll never admit

Thanks Andy and Bert!.. I ll check the spark plug for problems.. But.. at the same time i do not find any other symptoms of pre-ignition (like power fluctuation or so). Thanks for your info..

And Bob.. Good to have that input... but i checked all visible bolts on the outside, and found things to be good... anyways i ll recheck all possible connections...

And Ky... i ll be happy to admit my mistakes.. coz my aim is to learn something out of all these conversations (meant about automobiles and nt abt arguing).. and regarding the FINGERS u showed me through that image...

I take the THUMB and u take the rest, specially the MIDDLE one!