CBR 600-Knocking.

Echo Jayden · 09-07-2009, 11:35 PM

I was given a 98 CBR 600 with some knocking sounds going on when it runs. I have had people tell me it's a bad spark plug to a bent rod to I have to rebuild the top end. I have taken off all the plastic, down to it's bare bones. Any ideas from actual bike people? Thanks.

Charles486 · 09-07-2009, 11:39 PM

its gonna take more than "knocking sound" to get much help, have you done any engine work before? what do you know about the bike, wouldnt hurt to swap out plugs filters etc if you dont know the history

Echo Jayden · 09-08-2009, 1:17 AM

It was driven pretty hard before I got it. It was rev'd pretty high alot-wheelies and burnouts. My younger brother owned it before me and he used it as his daily transportation as well as his fun bike. Right before he gave it to me, he did an oil change. As I drove it back to my place, I heard the knocking sound as soon as I started it. He said it had never done that before. The sound would intensify when I gave it gas, and then decrease as I let up. I have done minimal amout of work on engines-oil changes mostly-so I'm looking at this as a learning experience. Thanks.

Charles486 · 09-09-2009, 2:02 PM

that doesnt bode well, you can always try a plug change but it sounds like something more internal, particularly if it matches the revs.

Echo Jayden · 09-09-2009, 4:14 PM

That's what I was afraid of. Any suggestions on where I should start looking?

Charles486 · 09-09-2009, 4:50 PM

im not especially familiar with the 98 motor but if you can remove a cover and manually turn the crank(usually the sprocket is a good place to do this) KEY OFF you may be able to feel/hear whats going on without it running, that would at least rule out plugs. I would also check the timing, if you don't already have a manual its a very worthwhile investment.