camchain tensioner on a 98 CBR600F

Hi all,

I've just bought a 24000 mile CBR and I'm checking the valve
clearances but I cant work out a bit in Haynes about the camchain
tensioner.

"Retract the tensioner plunger using the special tool"

Any idea why I need to do this before checking the valve clearances?
It doesn't seem to stop me getting to the point of checking them all
in turn while cranking the engine over with a socket in the
crankshaft.

I'd be more tempted to ignore it if all the clearances were ok, but
weirdly, all four valves on cylinder 4 are a bit narrow so I'm looking
for excuses to avoid having to sort them out... and maybe the fact
that I haven't retracted this plunger is the reason...?

Cheers for any help
Steve

 

You only need to retract the tensioner if you're actually moving the
cams (can't remember if a '98 CBR6 has shims under the buckets or on
top). As you say, for simple gap checking, there's no need to touch it.

 

Thanks.

It has shims under the cams (not sure what the buckets are you
mention).

It looks like I'm going to have to take the cams off anyway if this
doesnt explain cylinder 4 gaps all being tight. Arse!

Cheers
Steve

 

Camchain tension will not affect valve clearances, so if they need
sorted, sort them. If you don't, you'll burn a valve sooner or later.

 

Buckets are just that - small buckets inverted over the end of the
valve.

The adjusting shim can either be on top of the bucket or underneath it,
on top of the, which is more secure but means the cams have to be
removed to change the shim.