Rhythmic knocking under acceleration

[Pantera101]

Hi.

I have a 2003 Busa which I've owned without problem, and many smiles, for the last two years. I took it out yesterday but noticed a rhythmic knocking sound coming from below me whilst under acceleration. The faster the bike the faster the knocking, and when I roll off the accelerator it disappears (or at least goes a lot quieter).

I am not technically minded at all so any ideas on what it could be? I am assuming a garage visit will be required but would be nice to have some forewarning before any bills come it!!

Thanks
Darren

 

[BusaWhipped]

When's the last time you checked the chain?

 

[Pantera101]

To be honest, last checked in March by George Whites during it's service.

 

[rickneuhaus]

pull your side panel off and listen by the injectors with a plastic screwdriver head or something up to your ear.... this will tell you if it's valve or tappet issue

 

[E Zurcher]

Does the knock track with the engine speed or under load? If so it may be a bearing or piston slap.

 

[Pantera101]

Thank you to all for feedback so far, it is much appreciated.

The chain tension seems to be ok and within correct tolerances for tightness. I only notice the knocking whilst in gear and under throttle, and the knocking quickens as the bike speed increases. I will have to wait until the weekend to check the valves or tappets to see if the fault is there.

 

[newman]

You in England. If you are I brought my bike from George Whites, had my first service a few weeks ago, they only filled my oil up to the lowest level, had to go out and buy some more oil and top it up.
Like you I'm not technically minded so I can't help you with you problem, but good luck anyway.

 

[chrias]

I know this is an old thread but my 05 Busa started doing the same thing and it happens around 4k rpm. It kind of quiets down at 5-6k rom but it's still there and it only happens under load. Revving it in neutral doesn't produce the same noise and it only happens under load. It kinda sounds like a marble spinning and hitting a bump in the can. Kind of a rattle/knock.

Would the cam chain tensioner make a serious noise under load? I don't hear the knock/rattle at idle. I have to shift gears at 3500 rpm so I don't hear that noise.

 

[mikelr]

You have something loose on the bike, from 4000-5000ish rpm is the "buzz zone" for this motor and if it ain't bolted down tight it will rattle in that rev zone...