valve clearances 1998 CBR600F

Hi,

I've just bought a 23,000 mile CBR600F - my first bike with shims -
the GSX600F I've had for 10 years has screw adjusters. I've checked
the valve clearances and they are on the service limit...

Haynes says 0.19-0.25mm for the exhausts - I have two valves which
allow the 0.18 gauge through, but not the 0.20 gauge. i.e. they are
either 0.18 or 0.19mm

Removing the cams is a 4-spanner task according to Haynes so I'd
really like to avoid it.

What is the percieved wisdom among the home mechanics with experience?
(not the 'just take it to the garage and pay the bill' people) Should
I go to all the effort of fixing it, or leave it?

I plan to keep the bike forever, and maybe never check them again (I
was told the clearances hardly ever change on this engine by a
mechanic who is usually over cautious if anything)

Cheers for any learned opinions

Steve

 

I'd adjust them. If you don't do it now, you'll almost certainly have
to after another 10k miles, & possibly a lot sooner. If you don't
adjust them you'll just have that nagging doubt, & end up checking them
again in a few months anyway.

It's not a difficult job, just time consuming.

--
Krusty
www.MuddyStuff.co.uk
Off-Road Classifieds

'02 MV Senna '03 Tiger 955i '96 Tiger '79 Fantic Hiro 250

 

says...

If the clearances have gone tight then get those two you mentioned
sorted. Your mechanic is kinda right, CBR600 clearances rarely go out by
much, but it's worthwhile doing them if you want to keep the motor good.

If you've checked them then I assume you have the cam cover off, so
actually changing the shims is just the next step on. It's not that
difficult if you know what size shim you have, what valve clearance that
shim gives and what shim is required to get the clearance back to where
it should be. In the manual there should be a chart that lists the
correct shim if you know the first two values. You do have to be careful
of timing up the cams once you replace them and making sure you torque
the cam cap bolts to the specified value. The rest is 2 spanner work.

Timing up the cams is made easier by tightly cable tying the cam
sprockets to the chain before removing them, making sure you never turn
the engine while they are out. Always treble check the cam timing is
correct before slowly turning the engine by hand after reassembling the
cams, and camchain tensioner, but before you replace the cam cover. Only
finish the reassembly and attempt to start the engine once you are
satisfied that everything is back together correctly.

Get stuck in and do it.

--
Lozzo
Triumph Daytona 955i SE
Suzuki SV650 K3
Honda CBR600 F-W
Yamaha SR250 SpazzTrakka
Suzuki GSX-R750L

 

Those clearances you quote really are on the tight side, so I'd get it
done properly.

That's true, but if I was going to run it for ages and ages, I'd want to
make sure it was running spot-on clearances to start with.

 

Those clearances you quote really are on the tight side, so I'd get it

Thanks guys. It's the answer I didn't want, but that doesn't make it
wrong!

Looks like I need to bite the bullet and sort them :-( Bollox. I
was all comfy on the sofa...

Thanks for the guidance Lozzo. I'll be really careful. (I managed to
recently destroy the wifes Fiesta engine with a rather unfortunate
valve on piston incident...) <hangs head in shame>

Cheers,
Steve

 

I did this also, did not listen to my Ford Mechanic who said Zetec engines
come out of the bottom, bollox said I, the older type came out the top and
by undoing the bottom pulley wheel so did the Zetec, but alas it has no
woodruff key and the timing chain slipped, whoops.....bent valves.

Alan

 

says...

I've just had a quick flick through the workshop manual. You only need
to remove the exhaust cam, the inlet can stay where it is. On some
bikes, later Gixers for example, the cam caps are one huge item that
clamp both cams down in one hit - on the CBR you have two seperate ones
for inlet and exhaust.

The Haynes manual tells you to remove the sprocket from the end of the
exhaust cam before taking it out, you *may* not have to do this. First
remove the 3 bolts holding the cam chain top guide in place, then like I
said, cable tie the sprocket to the camchain on both inlet and exhaust
cams to stop it from moving, undo the exhaust cam cap bolts in the
correct order as shown in the book and see if you can just roll the
exhaust cam up and backwards to keep everything attached, making life
easier when it comes to putting it all back together. It might not be
possible to simply move the cam up and back with it all cable tied in
place, in which case just follow the manual and remove the sprocket.
Either way, it's not rocket science and only adds about 20 minutes to
the job, it's just my way saves on pointless arse-ache if it can be done
that way.

Once the cam is out of the way, all you need to do is lift out the
buckets from the ones that need attention, take the offending shims out
and swop them for the correct ones, then reassemble. Just make sure you
don't turn the engine over while the cam is out and treble check the
valve timing before you refit the cam cover.

--
Lozzo
Triumph Daytona 955i SE
Suzuki SV650 K3
Honda CBR600 F-W
Yamaha SR250 SpazzTrakka
Suzuki GSX-R750L
Suzkui TS50X

 

Not forgetting to stuff clean rag into the cam chain tunnel etc. to stop
stray screws and what have you being dropped in there.

 

says...

Not so bad on CBR6s because the camchain tunnel is at one end. Simply
remove the right hand engine cover and retrieve the lost bits.

--
Lozzo
Triumph Daytona 955i SE
Suzuki SV650 K3
Honda CBR600 F-W
Yamaha SR250 SpazzTrakka
Suzuki GSX-R750L
Suzkui TS50X

 

<shock>
It is???

Is your 1100 a little tired?


In what ways is the Honda superior.

 

I don't think so.

Reversing the question, the screen and fairing on the K is far
superior... but that's it.

The Pan wins on:

- Handling.

- Suspension.

- Braking.

- Riding position.

- Stability (K1100 is top heavy when fueled and is tall).

Face it, the K harks back to the early 80s whereas the Pan is a decade
younger. It shows.

The engine *might* be a little better on the K. Not really sure.
They're both nice and tractable.

 

They need modding I agree

Upgrading makes all the difference but costs a few bob

This makes me wonder. The K11 with good disks, goodridge hoses and the right
pads should be about the best brakes you ever tried.

Hmm I found the standard K11 bars too high and set back too. The footrests
slightly too far forward.

Relates to the suspension issues.
Improved again with RS size wheels and good radial tyres.

 

Not with those long forks and rubber mounted handlebars.

Yes... but the Pan doesn't need any mods; that's the point...

 

That doesn't change the braking characteristics though does it?

I'm repeating myself but a Hagon or Progressive fork conversion (or a trip
to Maxton if you are flush) and fixed mount bars cures *so* much.

Actually I would love to do a factory trip to Maxton with a K11. I recall
Monz doing this with the TL1000 and it cost him about a Grand so it would
need to be a late and mint K to be worth the expense.

Oh I realise this but I never liked the fairing, the handling, the
complexity, how hard it is to work on, the spares situation (in comparison)
and it's a Honda...

 

Brakes work better than they did, for sure <eyes RD400> but my K11 was like
hitting a brick wall, not quite in the AP class but good nevertheless. The
bar or suspension never made me think they were anything other than great.
To be sure, until the rubber bar mounts were shimmed out it could snake
under you some.