Engine removal...pain?

Hi all,

Bit of a longtime lurker in here but it is now time to poke my head
above the trench, mainly because I could do with some advice ;-)

I recently bought a bike from a private seller - namely an 02 Kawasaki
ZX6R 636. Mint condition, FSH, took it for a ride - all fine. However
before taking it away I did notice that the chain seemed very tight -
no problem I thought, I'll loosen it off when I get home. Except I
forgot of course, and now 2 weeks later I'm getting a horrible
sounding whine. Now given that this whine is matched in pitch with
road speed, it occurs when the engine is under load (i.e. when
accelerating) and that the chain was tight to begin with, I've got a
nasty feeling that it's the dreaded output shaft bearing (unless
anyone has another suggestion?).

Now, if it is said bearing I'm tempted to replace it myself. I've got
hold of and have been checking out the service manual - which leads me
to a few questions.

1) The manual mentions some special tools are required - namely a
engine mount nut wrench + jack, flywheel & pulley holder and a bearing
puller. Can I get away without these special tools? I have the usual
stuff already - sockets, torque wrench, hammer

2) Any other gotchas that I need to be aware of?

Thanks in advance!

Stu

 

Is the chain too tight? If so, I'd say there's at least a fair chance
the sound is coming from that. Loosen it off and see if the noise
goes away.

I'd do a lot more investigation before I planned to drop the engine
out. Like, removing the gearbox cover, grabbing hold of the front
sprocket and checking for any play.

You shouldn't need any of these just to split the cases and sort a
gearbox bearing:
- remove all ancillaries (plastics, tank, carbs, exhaust, etc)
- remove engine
- remove clutch
- turn upside down
- remove sump and bottom crankcase half
- sort gearbox
- assembly is the reverse of disassembly

But I'd actually be pretty surprised if you've fucked a gearbox
bearing that easily.

 

Cheers Champ.

The first thing I did when I remembered about the tight chain after
hearing the new noise was loosen the chain off - noise is still there
unfortunately. I must admit the chain does need replacing - it's got
a number of tight spots so I'll try replacing that first and see if
that helps...will check the front sprocket for play at the same time.

The noise does appear to be coming from the general area of the
gearbox, which is what made me think of output shaft bearing along
with the tight chain. Not losing any oil though...it's just noisy!
Is there any chance it could be a wheel bearing, considering the noise
only happens when accelerating?

Ta

Stu

 

As Simon says, you'll have to change the chain and sprockets anyway,
so might as well do that first. Chains can give rise to all sorts of
noises [1], especially when knackered.

It could be, tho in my experience wheel bearings only make a noise
when they're proper fucked. Easy to check, tho, so worth doing.

[1] Chain noise is a significant factor when motorcycles are
homologated for the EU noise regs.

 

Yup I'll do that this weekend, I'll check the wheel bearings at the
same time too. thanks for your help both, you can probably tell I'm a
relative noob to bikes but thankfully I do have a small sprinkling of
mechanical knowledge...

Cheers

 

I think you may well have.

However, recently there was a good thread here no how to replace said
bearing in situ, without removing the engine. Bonwick dispensed a load
of advice which turned out to be exactly on the money (as you might
expect), and the job was done.

A Dremel and stud & bearing fit featured prominently, IIRC. Google for
it, or click your heels three times, saying "Don't mention the nuclear
subs", and he'll turn up here.

Bear in mind that any total engine strip will always work out much
pricier than you budgeted.

 

Yeah I think I came across that thread recently whilst doing a search
for the symptoms on my bike. Sounds like it worked well, if a bit of
a bodge...

Just out of interest why do you say a strip will always cost more than
is budgeted?

Cheers

 

It's a sub-section of the same law that saws that fixing the used bike
you've just bought will cost more than you budgeted.

Even if you don't underestimate or forget the price of every last gasket
or oil seal and drop of fluid, even if you swear that you will not
replace any item other than the offending component, you'll wind up
replacing things like camchains and tensioners "just because it's silly
not to while it's apart", or you'll discover that the mechanical damage
is way worse than you predicted.

Trust me on this. It always works out this way.

 

Output shaft bearings don't normally whine, they grumble quite nastily
before they let go. If the bearing has gone, it' usually preceeded by
an oil leak from the oil seal around it.

 

Not sure i'd say it's a grumbling noise...it's kinda like a harsher,
lower frequency version of normal gearbox whine, if that makes any
sense....hard to describe...

Fingers crossed it's just a knackered chain tbh! ;-)

 

Yeah good point - I seem to recall that I ended up spending quite a
bit on replacing a cylinder head gasket on my old banger back in the
day...

 

No he won't.

That one was just a final attempt before stripping and I got as much
satisfaction out of it working as I did from winding up that stupid
**** who'd wandered in from the classic group. The OP in that thread
did a good job when you consider all he had was a few posts from an
internet newsgroup to show him how to do it.

 

I thought much the same, actually.

 

Well it's not a knackered chain. Finally managed to get around to
putting the new chain on yesterday - it appears to be pretty much the
same situation. While I was there I checked the output shaft for play
- there appeared to be none at all. I did notice some "clunking"
whilst spinning the output shaft by hand - should it be smooth with no
noise at all, or is this normal? There is no sign of the bearing seal
coming off either...

In a possibly related matter, I ran the bike in first on the stand
with the new chain and the chain was jumping/lurching around quite a
lot! Also noticed this in first gear with the clutch out - bike kind
of lurches quite a bit. Not sure if this is related or a different
issue??

Anyway the original noise is quite a bit louder now so something is
definitely on the way out - as mentioned before it's on the output
side of the gearbox...

Cheers
Stu

 

Using the patented Mavis Beacon "Hunt&Peck" Technique,
typed

You did change both sprockets, yes?

 

Certainly did - new front and rear sprocket and chain. Also cleaned
all the gunk that had built up in the engine sprocket cover...

 

Ah, ok. I guess I was surprised by how much it was jumping - seemed
to bog the engine down a little too. I'm guessing that this is
probably due to the fact it's quite a highly tuned engine? The idle
itself seems smooth enough - pretty constant rpm. Only have my old
CBF600 to compare it to, which wasn't the most powerful thing in the
world (or indeed exciting) ;-)

Righto I'll give that a go. Any kind of shiny bits in particular I'd
be looking for?

Ta