WTF is wrong with my bike?

The bike broke down some time ago, I say broke down, it started making some
very unpleasant rattling noise from the engine. So recovery was arranged,
bloke had a listen and pronounced "cam chain", which was kinda what I felt
it might be.

So, bike into the kitchen, and take a look.Cam chain is nice and tight, a
little lateral movement but I can't pull it away from the cogs, which I
imagine to be a good thing. Does this eliminate the cam chain as a source of
the mystery noise, or do I need to do something else to it?

If it's considered unlikely to be the cam chain, any suggestions on what to
check next? Having just bought and installed a new boiler, I'm lacking the
funds to "get a man in".

 

What bike is it?

Could be the tensioner - sometimes they rattle when cold, and then
decide to work and the rattle goes away.

Might not be camchain or tensioner at all, in which case it often starts
getting expensive.

 

My recent fuckwittedness on the Z400 was initially diagnosed as being
camchain rattle, turned out to be the screw and locknut working
loose. I ended up having a top end rebuild courtesy of Speedy Spic
Engineering (tm).

I know your bike has shims but when were they last checked?

 

Oh yeah, ZX6-R G1

The tensioner that's in is about 12 months old. I've got a new one here
anyway, so I could bung that in and see if it helps.

That's what I thought. Suggestions on what to look at next?

 

About 12 months ago. I may as well take a look at them, since the bike is in
bits across the kitchen floor.

 

Hmmmm... alternator drive, if that's chain....

It depends where the noise is coming from. A camchain rattle sounds very
different from a valve whose clearance is too big, if you've heard both
sounds.

FWIW, my money is on the tensioner. They changed the design of the ZX6
tensioner from a ratchet type on the Fs toa Honda screw-in type (like a
CBR600) on the G1 and it stuck and rattled (like a CBR600). They changed
it back to a ratchet type on the G2, and all was well. The G2 type is a
straight retro-fit to the G1. If you replaced the original tensioner
with another exactly the same, this is almost certainly your problem.

All G1s should have been converted under warranty, but.....

 

Clutch bearing: Does the rattle stop if you pull the clutch in? Is the
clutch centre nut loose?
Gearbox final drive bearing: has the chain been overtensioned?
Compression: is it even across all cylinders? Possible stuck valve?
Alternator rotor come loose: Check clearances.

HTH

 

No, that's a direct drive (I think)

I've not, so I'm guessing. I might as well check the valve clearances.

The replacement was ratchet type one. The noise was first heard whilst the
bike was warm (25 miles at a ton plus).

So the next thing on the list is the valve clearances...

 

No and dunno.

Not as far as I know, but noise is present when in neutral or in gear.

No idea. Will have to borrow a compression tester

Worth a look.

I'll check the valve clearances first, cos I reckon I can manage that by
myself. After that I'll start my way down your list. Ta.