checking valve clearance

Today, I have mostly been servicing my old CBR1000F. Unfortunatly
things started to go ugly when I marked the fairing removing the tank,
and I lost a bit of the rubber mounting .. Bugger! ( well the stupid
thing must be in the garage some where though)

Apart from this everything else seems to be going ok. I fitted the new
K&N air filter, then drained out the Engine oil and coolant. I replaced
the slimey goo in the hydraulic clutch with fluid, then spent an hour
fiddling with the f'f'ing throttle handgrip after removing it to oil
the cables.

I've got the rocker cover off but so far as I can tell the valves
don't need adjusting, So can this be be right for a 42k mile bike ? I
know I've never adjusted them in 22k miles and the gasget looks like it
has the factory sealant on it . I'm going to put it all back together
tomorrow and go and ride the bloody thing ! It's not nice seeing it all
in pieces. I always thought it was the cam chain flapping about but
looking at it with the rocker cover off it' has no play at all.
Simon

 

In uk.rec.motorcycles, mr p belched forth and ejected the following:

When I looked at mine it looked ok.

I used a feeler gauge though.

 

Thanks for that. I have been googling and think I understand it a bit
better now. The clearance can actually get too tight if the valve has
worn into it's seat,and then they could overheat. You check it at TDC
when the valves both need to be fully closed.

Simon

 

In uk.rec.motorcycles, mr p belched forth and ejected the following:

"You're pissed, aren't you, Nicholas"

 

Shims? Quite likely; often shims don't need touched. It's always worth
checking at the recommended intervals though, just for peaced of mind,
because sometimes they actually do need attention.

 

Yeah, it's a swings and roundabouts kind of thing; conventional rockers
need adjusting more often, but they're easy to do and you don't get
caught out without the right sizes.

 

no shims, but it in the cold llight of day I can see that the exhaust
valves are a little tight. I'm going to have to have another go at it
when I get the honda tool though because it's so awkward ! If it blows
up before then I'll just go and buy that blackbird I always wanted

Simon

 

Shims ontop of the buckets, you know ones you can pry out and replace
without removing the cams are pretty good. I suspect though that
they're only suitable for low-revving engines (and possibly only for
large diameter shims-hence only 2Valve per cylinder engines?)

 

Same as the GS type. I find they don't change much, but it depends on
the pattern of useage - thousands of miles of steady riding causes no
wear, but a few hundred miles of giving it welly does. Luckily I've
built up a stock of likely sizes over the years. I always meant to
obtain a genuine tool for doing them, but the two screwdriver (one bent)
method works quite well.

 

In uk.rec.motorcycles, mr p belched forth and ejected the following:

It is fiddly but can be done with a 8mm socket and an allen key.

If it's not rattling like a bastard, I'd not worry about it blowing up.

 

Burnt said...

ZZR1100s have shims on top of buckets and there are sixteen - four per
cylinder - in an engine that revs fairly high.