Knocking sound CB600F, gets quicker when speed up.

[NearOn]

Noticed today after around half hour on my bike, it started making a loud.knocking noise from the bottom of the engine I think, the front end of the bike. It is loud in 1st and 2nd gear, then as you get quicker, the rest of the engine noise dampens the noise down, and it gets quieter but quicker.

It doesnt make this noise when idling in neutral. Some other people have suggested problem with chain, tight link, or sprockets, as it gets quicker the faster you go. Also I can feel the vibration from the clunk on left foot peg.

Any advice be great, cheers

[Guest]

whats the mileage, could be the bottom end is in need of attention (crankshaft)... might be time to find a hornet forum, see if its common..

[NearOn]

Mileage is 25k, already on a Hornet Forum and posted on there, just thought see what anyone thinks on here too.

Is crankshaft problem expensive?

[hammer5]

No illegal immigrant underneath is there?

[Guest]

Get a wooden handled screwdriver, place the tip on the bottom end of your engine, and your ear on the wooden handle and see if you can hear a pronunced knock coming from the engine, another good test is to ride you bike up a steep hill at low speed in to high a gear, if the knock gets worse it will probably be your crank (good test for camchain rattle as well) sorry but if it is your crank it will be expensive, Are you sure it's not your brake pads rattling. or a loose exhaust manifold?

And check that chain for tight spots, use a rule placed against the under side of your swing arm turn the back wheel a couple of inches at a time and measure chain slack against the rule.

[Guest Hodgy]

It sounds like the chain, take the front sprocket cover off and check there are no teeth missing and it's not loose, and check the whole of the chain for tight spots.

[NearOn]

Thanks for replys, most people on here and elsewhere are saying check the chain for tight spots, now I tried to follow the Haynes manual but just dont get what im looking for, and how to get rid of any tight spots? cheers

[Guest]

undo the front sprocket cover and rotate the wheel.. you should see any links that dont smoothly follow the small sprocket, hence being tight or stuck, you need to clean these, and waggle (techie term) them to free them up..

depending on how gone your chain is (adjustment) might be easier to get a new chain and sprockets.

general cleaning and regular lubing will help prevent tight spots, ooo-er...