Hi guys,

First off, thanks for all the incredibly useful postings on the site. They've been a real saving grace whilst getting my baby back on the road after some time in storage.

Next I'm wondering if I might for a little assistance with, what are hopefully, the last few niggling items I'm struggling with:

1) My baby has sat in storage for quite a few years (kids and a divorce will do that, ya know), and she's having some re-teething issues relating to engine(?) noise (fairly strong knocking at idle).
2) She's also not able to idle, but revs smoothly in neutral over 1100 or so upwards, and also has a strong pull up through the gears.
3) I'm having a bugger of a time with the electrics. Everything was working great when I first put a battery back in her, but now I've lost dash lighting on the right side of the cluster, along with the Neutral light, clock and gear position, as well as flashers not working. Everything else electrical seems to be working fine.
4) Lastly, I've been trying to bleed the front brakes, but am running in to a big problem with pressure from the front master (all lines disconnected from the cylinder, just pumping to build pressure, then releasing and repeating, but to no avail).

I realise this a big shopping list on my first posting, but I'm really at a loss here, so all commentary gratefully appreciated.

Cheers, Alex.

Regarding your items 1 and 2, that really sounds like a vacuum leak to me. It will cause the engine to labour at idle and rattle, and obviously idle lumpy. Potential air leak areas are the rubber manifolds (two sets) above and below the throttle bodies, where these can crack over time. Also check the vacuum port caps - are they all there, are they cracked? Also the crankcase vent tube is a typical cracked problem.

Easiest way to check the vacuum leak theory is to spray some carb cleaner in these areas, if the idle increases, it's picking up the flammable cleaner and burning it. There is the leak. Another way to test is with a propane torch, point the spout towards the same areas, expect the same results as carb cleaner. Note, do not have the propane torch ignited when doing this. That would seem obvious, but...

I've got nothing for you on #3.

#4 is a little unclear, but sounds like you're not building any pressure? If so you likely need to put in a master cylinder rebuild kit.

Hi Alex,
If you have drained all the old brake fluid out of the system, the easiest way to get new fluid in is by vacuum bleeding. Fill the reservoir, and open the bleed nipple on the calliper. Get hold of a large syringe, (50 or 60 milliliters) - should be available from a pharmacy or vet - and attach it to the bleed nipple with a bit of rubber tubing. A few turns of PTFE tape around the threads of the bleed nipple will prevent air leaks. Pull out the plunger of the syringe, and shut the bleed nipple. Repeat until you get fluid into the syringe. I used this method several times on car brake an clutch systems before we got a compressor driven vacuum bleed kit - looks like a spray gun but works the opposite way.
You may find that the master cylinders start to leak after changing the fluid, (mine did when I replaced the dirty looking fluid of unknown age) in which case you will have to either fit a kit or replace them. Looking at the state of mine when I opened them I opted for replacement.

Hi Alex
I'm no mechanical genius, but had similar problem. Go with the syringe or buy a bleed kit with a small valve on the end (Auto Pro shop has them).
I took a chance and bought a new piston innards from Motobins and pulled the old one apart. Amazing the crud in the springs and tiny holes. For sure I'd clean it all at least, and if I can do it, anyone can. You need a pair of
circlip pliers to get the clip out. (Auto Pro. no I don't own them but am slowly buying their stock HA.) Oh and a can of Brake Fluid cleaner, and a set of Allen key rachets and some heat paint and nifty small set of spanners. Man, I could go on but my wife might see this.
Regards RT.

Hi Alex,
The above comments are good I would look carefully at the rubber in the tank which holds the pump they can break down if left a year with alcohol loaded fuel (not sure if Aussie has yielded to that lunacy yet) but in respect of item 3 that sounds fairly straightforward to treat. Go and do a search of the site go read http://k100rt.aforumfree.com/t223-led-lights-in-the-instrument-pod-plus-sealing-out-the-moisture?highlight=LED+lights+in+the+instrument+pod+plus+sealing+out+the+moisture

That was an earlier posting of mine regarding sealing the pod, a big problem with the early bikes was water got into the cluster and gave bad connections leading to all sorts of issues. I suggest you go through every connector on the bike with DeoxIT from Jaycar, get the two bottles of liquid like nail varnish bottles with the liquid in not the small spray cans there is not enough in there. Then do every connector including the mega connector on the back of the cluster and then whip the cover off the cluster as described. Treat every electrical connector in the cluster to the full clean that should restore performance to as new. Consider fitting the LED conversion except for the alternator light.
Regards,
K-BIKE

Avenger GT wrote:
You may find that the master cylinders start to leak after changing the fluid, (mine did when I replaced the dirty looking fluid of unknown age) in which case you will have to either fit a kit or replace them. Looking at the state of mine when I opened them I opted for replacement.

This triggers a memory in my sluggish grey matter: An old mate of mine who was a mechanic for yonks suggested to me once that oftentimes when people are bleeding their brakes they pull the lever too far or depress the pedal too far and actually damage internal seals. His theory was that (assuming you haven't rebuilt the system and are simply bleeding the brakes) the normal lever actuation or travel is rarely as far as you are pulling or pushing when bleeding and so a small amount of crust builds up in the bore at the end of the piston's normal travel. Under normal use the seals don't come near this hardened gunk, but under pressure of bleeding (and eagerness or hamfistedness) they do, leading to damage and eventual leakage, often right as you are bleeding the system. He suggests never going to the 'stop' when bleeding. I have taken note of his advice and this is the way I bleed hydraulic brake and clutch systems, patiently, gently and never going all of the way to the end of the travel, with good luck so far.

hiya alex ....

have you tried putting the connections back together ,,,,so there is some vacume on the release of the lever ...im pretty sure there is a certain amount of resistance required before the master will suck new fluid into the front of the pump chamber

nice touch twb ...see, there is far more to learn from these "gems" of information... our fathers and old hands ...thanks for reminding us of that fact.
i would have to congradulate all out past techos for their wisdom in keeping what was going ....going ....many of them were brought up with the vision that not all things are available all the time .

i guess our bikes are after all, at the end of or nearing "all things rubber" ....passed their "used by date"

cheers bloke ......love the wordsmithing

Two Wheels Better wrote;
"This triggers a memory in my sluggish grey matter: An old mate of mine who was a mechanic for yonks suggested to me once that oftentimes when people are bleeding their brakes they pull the lever too far or depress the pedal too far and actually damage internal seals."

Not so in my case, I never pump brakes to bleed them since we got the vacuum kit. The buggers just decided to expire.

Thanks for the suggestions, gents. I'll be tackling (and hopefully resolving) the idle and electrical issues today, thanks to a couple of cans of carb cleaner and contact cleaner, and I'll try to keep everyone updated on the results of that low end knocking noise. (That last one really has me worried. I hope she's not making death rattle noises).

Ok, mini-update.

Bike WILL run, just not at idle. In order to get it to catch, I've got to have the choke pushed fully open and then crank. After about 30 seconds I can let my finger off the choke and it won't stall immediately, all of which leads me to believe the generally commentary about vacuum leaks was spot on. (Off to buy carb cleaner in a few minutes, along with a "power bleeder" from Super Cheap Auto (or one of its many cousins out here in the Western suburbs).

Electrical is still worrying me as I've replaced all the fuses and had no joy with the right hand side lighting on the cluster coming back to life.

Mechanically, I'm still VERY worried about that low end knock at idle (see above).

Alex, concentrate on one issue at a time. To me I would be hitting the poor running issue first. I think once that is repaired you will find the motor runs quieter, and that 'knock' may just go away. How many miles on your bike? If it was quiet before you stored it, I doubt anything came apart inside the mill while it was sleeping.

Well the speedo has about 30K on it, but there wasn't a service history with the bike and given the replacement history of speedos under warranty, I suspect this bike has some serious KMs under the covers.

Believe it or not, I have seen on the 'net where mileage travelled can be worked out using the wear on the rear brake pedal.

It starts with slight wear on the "bumps" on the outer corner of the pedal and goes up from there. Apparently it's fairly precise.

But you'd have the usual wear points, worn grips, footpeg rubbers, shifter rubber, area around the ignition switch, wear on the bolts etc.

The story about not fully depressing the pedal or lever on an old badly maintained brake system is so true. I recall years ago when I started working on cars a mate had really spongy brakes and dark brown fluid so I volunteered to bleed his brakes and flush with new fluid. All went well until we had finished and there was almost no resistance on the pedal let alone spongy. When I stripped the master cylinder the rust in the bore which was not normally swept by the piston absolutely SHREDDED the seals GRRRR! A lesson I learned just the once and have used pressure bleeding or an occasional vacuum bleed since then.
Regards,
K-BIKE

The front master cylinder was dissected this afternoon and was filled with sludge and crap. A vigorous cleaning later, but I've still got no pressure to the front lines at the bleed nipples on either side. I suspect it's time to order a master cylinder re-build kit :-(

i hope you have filled the lines from the master cylinder alex ...using the pump method by the master cylinder alone seems to take forever to acheive .

charlie99 wrote:i hope you have filled the lines from the master cylinder alex ...using the pump method by the master cylinder alone seems to take forever to acheive .

Bloody good point actually, but what with the spotty pressure from the front master cylinder, I still reckon it's time for a re-build. (Fingers crossed).

After much faffing about, the brake problem actually turned out to be brake problems. Firstly, the circlip which retains the piston assembly in the brake housing on the handlebars wasn't exactly broken (e.g. it looked intact on visual inspection), but had rusted through so much at the thinnest points, each time the brake lever was pulled, it flexed and wept fluid around the end of the piston. Next, after disassembling the entire bloody thing, I found the bore filled with crap which had compressed so much the sludge had turned in to varnish and blocked the port in to the upper chamber. Finally, it appears the bore itself was actually worn out of round, and even after installing a brand new re-build kit, I still had no pressure.

Luckily, as part of an eBay purchase for the entire handlebars with all switches, brake lines, wiring and the brake master, I was able to salvage the brake master cylinder, vigorously clean it out, sand it back to bare metal, re-spray it, then install the new re-build kit in it, along with a new reservoir o-ring of course, and now I've finally got working front brakes!

An absolutely epic two weeks of troubleshooting b.s. but I'm finally there.

Next up, that nagging electrical problem. As I explained previously, the right side speedo back lighting, along with the 4L fuel indicator light, flashers and a few other lights, all quit on me about two weeks back. Luckily, I ordered an entire wiring loom plus electrical control box from the same breakers I got the handlebars (see above) from. I replaced the flasher relay, which has fixed the indicator problem, but I'm still bereft of the right side speedo back lighting, 4L indicator light, and a couple of other lights. This after swapping each relay in the control box, one at a time. My best guess is that I'm going to change out all the fuses (again), and if that still doesn't work, disassemble each wiring connector, spray them down with contact cleaner, then re-assemble them and keep my fingers crossed.

There was a glimmer of light in the electrical department though. The broken hazard switch which was on the bike (early 3 connector type), was pulled, I soldered new connections, and now it's been re-installed and works like a champ!

By mid-week, this week, I should (HOPEFULLY) have the last of the gremlins worked out, and have my baby back in fine working order.

Once again, thanks for all the helpful suggestions, and feel free to comment if you've got any ideas concerning my remaining gremlins.

alex ....if i can add a word of advice that i have recently acquired the knowledge, through the posts on this forum ........contact cleaner or electrical cleaning sprays do not always work ......i really do recommend the "deoxit "stuff ....cleaners may well swab off some of the gunk around electrical connections ....it still doesnt clean "chemically" as the deoxit does ...

i have found that contact cleaners usually remove loose gunge grease etc ...but you really need to lossen it first physically before applying ...it seems that this dexoit stuff actually promotes the disolving of the corrosion itself ..leaving bare (whatever ) contact between the connections

i recently had a dell lappy that was a mystery fault in the charging circuitry ,,,after dissasembling the whole thing ...i chased the issues back to the power input socket ....after applying deoxit to the actuall input power connections (2 weird little micro spade type doovas ..locked in a plastic connector and equally small plug pins ) the thing sprang to life ...after charging the internal battery pack

keep at it mate,, dont give up...seems as thought the list is getting smaller ... cheers

btw ...hey thats a good result on the brakes huh ?

Good work Alex, she will soon be there ready to go.

BIG D

If various lights or functions are not working I would suspect a problem with a ground connection. So, as per above, clean the contacts of the speedo. Good going!

I've spent the last few hours armed with contact cleaner, pliers and a bag 'o' relays and brand new fuses. I've cleaned every single connector in the harness, front and back, replaced all the fuses with brand new ones, re-seated all connections, and swapped out relays, yet I still have the same issues as before, namely, the Petrol 4L light, N light, Clock, Temperature Light, Gear Position LCD and right side green back lighting don't work (but used to).

I've also noticed, that with the petrol tank removed, if I crank the bike over for a few seconds I hear a click from the rear of the bike, and I loose all electrical power. If I take the key out of the ignition, and wait about a minute, I can then put the key back in and turn it to the third position and the electrical system starts working again (minus the items noted above).

I'm wondering if anyone else has run in to this sort of weirdness before, and if so, what was the solution?

hi, I had a similar problem, turned out to be bad crimp connector at the ground terminal.

Good luck

yankeeone wrote:hi, I had a similar problem, turned out to be bad crimp connector at the ground terminal.

Good luck

I'm assuming the main connecting point to the frame?

In my case it was the connector right at the battery.

Good news everyone, and especially good news for me.

In diagnosing the remaining options for the electrical problem, I decided to pull the instrumentation cluster and lo and behold, when I pulled the cover off to expose the two connectors from the loom, the one on the left was only partially engaged. A quick spray down with contact cleaner, re-installation and EVERYTHING electrical on the bike now works (almost). I did notice that the gear position indicator shows N well, 1 slightly dimmer, 2 dimmer still and 3 onwards not at all. Your thoughts?

woohoo .....some good news alex

if you search a little you will find the explanations about cleaning up the gear indicator switch ....(near the clutch boot - lever ) back of the gearbox....final drive area but i guess this doent solve the dimming of the indicator ...... did you get some "deoxit" yet ...highly recomend it .

Micro update: Won't idle

After fiddling about with almost every other part of the bike trying to address this issue, I got in to the guts of the machine this afternoon.

The rubber gaskets which connect the airbox with the throttle bodies, and those which connect the bottom of the throttle bodies to the engine are completely gone!

I called my local BMW dealer for a quote on replacement bottom rubber bits, and was told special order only $80 AUD each!!!!! OUCHIES!!! I haven't called about the upper ones, but I'm reasonably sure they're going to be less ouchy, but still sting.

Anyone have any ideas how to salvage this situation without taking out a second mortgage?

Alex.

P.S. Electrical system is now entirely functional, as is the braking system. Two down, two to go!

hmm maybe the tops could be replaced with a little radiator hose of the right dimensions ....cut to the right length without too many worries but the bottoms are a flange - to head mount (dohicky)...um neutral cure silicon maybe after a good scub up and degrease ....just a throught from the "rags" electronics guy ...rags = rough as guts

i think i remember twb importing some from overseas .....

great news on the electrics ....yay

Alex, try Motobins. The inlet manifold rubbers are around AU40 dollars each (plus postage).
I've used Motobins before...they're a good mob.

...and Motorworks for the ones from the airbox to the throttle bodies. Around AU9 dollars each (plus postage).

Probably arrive a week or so after you order.

Mate, have a search for the post "Leaky intakes - rough running" and you will see all you might need to know about how to do this job. Both Ned and I and others have done it. I might have also included the part numbers but lemme know if you need 'em. BTW, you can't just cut a rubber hose for the top bits (K100 at least) because they're stepped internally to fit both flanges, and get new clamps (four x 48.5mm and four x 50mm)! It really is the best way to seal these buggers up. Cheers.

Many thanks for the site links. Definitely way cheaper than buying stuff here in the Great Brown.

I have been working on a 85 k100 that had been sitting for 3 years, got it finally fired up and it rattled badly at idle but reved ok. i had to replace all throttle body to intake tubes and crankcase breather tube to cure all the vacuum leaks. Bike now fires right up and idles like it should. FYI I used brake cleaner to find the leaks, idles up when you get close the the leak.

Hi Alex. Thought I would put my two penny worth in. You are going the correct way for your brake problem, buying a repair kit. Clean out the body until squeaky clean. Fill the (clean) reservoir with new brake fluid and gently tap the brake lever, be prepared to do this for 5 to 10 minutes. You will see the bubbles coming back into the master cylinder as you pump. When no more air comes back, tie the brake lever 3/4 of the way back and go to bed, morning comes, wonderful brakes.
If you hav'nt cured the knocking on start up yet. Have you tried to balance the vacuums. If these are not correct you will get a knocking at low RPM. Plus the little air pipe on the back of the engine, under the air cleaner perishes and it sounds like a tractor.
I agree with club-c, do one thing at a time, that way you will know if you have cured or masked it.
Best of luck
Emlyn

Finally back from some time on the road for work, and have ordered replacement clamps (upper and lower), new lower and upper boots, along with all new O-rings for the injectors, and all new fuel and vacuum lines. Once they get here and have been installed, I'm reasonably sure my baby will be back in full working order.

One final niggle, and this is an entirely cosmetic thing, does anyone have a decent source for finding body work? Specifically, I'm after the scoop that sits under the engine, the wind screen deflector and left side lower faring (the piece that sits just above the cylinder head.

Cheers, Alex.

The best place for the parts is Fleebay (sorry E-Bay)

[quote="Alexander McCarthy"]Finally back from some time on the road for work, and have ordered replacement clamps (upper and lower), new lower and upper boots, along with all new O-rings for the injectors, and all new fuel and vacuum lines. Once they get here and have been installed, I'm reasonably sure my baby will be back in full working order.

One final niggle, and this is an entirely cosmetic thing, does anyone have a decent source for finding body work? Specifically, I'm after the scoop that sits under the engine, the wind screen deflector and left side lower faring (the piece that sits just above the cylinder head.

Cheers, Alex.[/quote

Hi again Alex. Motorworks here in the UK is the only one I use. They have a listing for a belly pan FAK03635 at £100 and a listing for a screen deflector FAK 51608 at £15. These are used parts. Link below to get into their site at the spoiler listing. I have not a clue what the postage will be down to you but has written above should be with you in a week or two. I would ring them up or send an email to find out if they have them in stock and what you will be paying. Hope this helps. Good news that you have your bike back on the road.
regards
Emlyn

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=fak51608&x=17&y=18

Parts all in from the good folks over in the UK, and found a long-term solution to those annoying single use clamps that secure the airbox to the throttle bodies. In digging through the local parts places, bearing wholesalers and the like, I found out that Suzuki has jubilee clips in 46 and 48mm sizes that *SHOULD* be perfect for securing the above, and which can be re-used in case the manifolds perish again (in another 25 years methinks). I'll post the part numbers for the pieces in question a little later on.

She's nearly there chaps, with pictures to follow soon!

yay.....good news alex

Hi all,

As promised I'm sharing the part numbers for those pesky re-usable clamps which secure the throttle body to the air box and cylinder head. They're all black, and come in two different sizes (48mm and 46mm), part numbers 09402-48208 and 09402-46208 respectively.

Hopefully this will helps someone who's re-building their baby in the future.Suzuki clamp 09402-48208

Ok folks, the never ending saga to bring my baby back to life seems to be never ending!

A complete fuel system tear down and re-build has her looking sweet, and fuel flowing everywhere it should and no places it shouldn't, but she still won't idle and still has that god awful low-end knocking sound.

Just for shits and grins I'm going to lob this idea around, and hopefully you'll have some feedback for me:

Could the low-end knocking/not idling unless the choke is held all the way open and throttle fully open as well be related to too much/too little oil and old fuel respectively?

I'd really appreciate your help resolving these fiddly buggers as I'm at my wits end with this.

Cheers, Alex.

Oil No, Fuel Yes. "Could the low-end knocking/not idling unless the choke is held all the way open and throttle fully open as well be related to too much/too little oil and old fuel respectively?" Following under the pretext that she has been running sometime and that you have followed the standard recommendation to clean all the contactors on the bike (!!!). For me this means a complete misadjusted throttlebody set-up, possibly part due to a faulty TPS. Do you hear it click when you open the throttle a bit?Duruing starting (with throttle closed) the initial mixture control is through the temp sensor in the AMS, with the closed TPS resulting in a slightly increased fuel setting. Once the motor gets above 700-750 rpm the normal system takes over.|Opening the choke takes the TPS past the '0' point and opening the throttle has air bypassing the throttle adjustment screws.If you have renewed the rubbers between the throttle bodies and the block, renewed the crankcase breather hose and all the injector rubber seals (or ensure they were good) it could be that there is an issue with the elbow between the plenum and the AMS (bugger to get it on right). If that all is good then you should have an airtight system between the AMS and the engine. Then I would go back to basic adjustments; all bypass screws to 1.5 turns open and synchronise the throttle bodies, making sure the throttle shaft isn't held back/stopped by the throttle shaft hanging on the end of rotation of the TPS or on the idle adjustment screw. Back to basics.On another track, you took care that the jubilee clip of the last unit is not obstructing the working of the choke/throttle shaft?

Guys Hi,

Oddly my k rumbles and knocks when on tickover, but i found that the tickover was to low by comparison to the tacho. It was saying 750 / 800 ish but did not sound happy. A mate checked it with a strobe light and meter and was closer to 650 / 700 so a tweak on the idle stop screw wound it up a tad and it is a lot happier now.

Early K engines suffered from poor idle shaft bearings and were upgraded to proper raced bearings i think from '86 onward and this know usually dissappears just after tickover .

I was told by Sherlocks that they very rarely cause a terminal failure of the engine. so i carried on last year covering 3000 miles around france and so far no big bang.

Hope this helps..

Ian

"Early K engines suffered from poor idle shaft bearings and were upgraded
to proper raced bearings i think from '86 onward and this know usually
dissappears just after tickover ."

Sorry mate, never heard of this before and it doesn't make sense as well. What's an "idle shaft bearing" let alone an "idle shaft"??

The only change in the engine bearing related was the change from a bearing with a loose fitting ring to one with a race.

A change to the bearing fit should not result in a noticeable difference in sound.

ReneZ wrote: Do you hear it click when you open the throttle a bit?

Yes, just as the throttle begins to open

ReneZ wrote:if you have renewed the rubbers between the throttle bodies and the block, renewed the crankcase breather hose and all the injector rubber seals (or ensure they were good) it could be that there is an issue with the elbow between the plenum and the AMS

Replaced everything and triple check fittings...all good.

ReneZ wrote:On another track, you took care that the jubilee clip of the last unit is not obstructing the working of the choke/throttle shaft?

Triple checked those buggers too, both on the bench and when actually fitting them. No obstructions.

Hello everyone,

Well I've spent the entire weekend up to my guts in the guts of the bike and found the following:

1) Poor idle appears to have been related to partially clogged injectors, that had become so due to old fuel turning to varnish. Despite having flushed the system thoroughly ages ago, I decided to pop the filler cap off and replace the fuel filtre. It was nasty too. Now the bike WILL idle (sort of), which I think is related to the next point.

2) In going back over what I'd already done, I decided to replace all the fluids and filtres again. Final drive oil was practically sparkling, transmission oil was horrific (coloured a sickly combination of melted chocolate and latte milk - with a horrendously burnt odour), and the engine oil was similar but not quite as ghastly. I also noted that the magnetic drain plug on the transmission was covered in metal filings. Once replaced, I cranked the bike over, and hear the same old, unsettling low end knock, only now with the old girl kind of idling, I could actually start hunting for the spot on the bike where that accursed noise was coming from. Sadly, I think I've found it. I think the final drive and/or transmission, are failing.

I'd very much welcome hearing from anyone who's experienced this type of problem.

Cheers, Alex.

P.S. Why BMW went with a dry clutch is beyond me.

your getting there alex ,,,one thing i have noticed is that if the bike is not running on all cylinders it does sound woefull...and all sorts of things come to mind .....personally i think you are hearing maybe the engine output shaft rattling with the uneven idle and weight of the clutch ....
try to work at getting a nice idle hapening ,,and then start to made other decissions after.
the gearbox oil colour sound remarkably similar to mixed dino and syntetic oils .
i would be getting a litre of castol epx 80-90 transmission stuff and replacing it (super cheep around $13 )....ps make sure that all the old stuff is drained completely ..might even be worthwile flushing it some more with maybe kerosene or something less sticky

BMW have had a dry clutch from the very beginning (1923) and only began to use a wet clutch with the F series (as it came from Aprilia/Rotax) and the newer K and now F800 series. From an engineering stand point it made practical sense in the boxer configuration (and still does) and the longitudinal K series (ours) as well. That would be some bloody great big massive lump of a unit if the wet clutch was buried in the middle somewhere there. At least the two huge lumps we have now can be separated! But that's the least of your worries at the mo'. It sounds like you're getting there. Good luck in rectifying your running problems.

Alex my advice is to get the engine idling and running smoothly before you go looking for the knocking. Get the injectors cleaned ultrasonicly and make sure the ignition timing is right and the throttle bodies are in sync and more than likely the knock will dissapear. An engine that is running roughly will have more rattles than a babies pram.
If it remains there are two places to look. First the main shaft rivits can work lose and rattle the solution is a later model shaft with 12 rivits.
Second if the spigot shaft on the gearbox is dry it can wear the splines and rattle, this rattle will often go when the engine is under load but dont ignore it.
Both involve removal of the gearbox but that in itself is not a difficult job.

Well, bikes and cars are always a labour of love, aren't they.

After MUCH more reading, calling dealers, breakers yards and a couple of mates, it appears the general conclusion is that the splines haven't been regularly lubricated, causing much mischief, and leaving me with a dilemma.

Since I don't even have a garage to work in (all the work so far having been accomplished in the forecourt of my block of units), and as the re-building of the transmission and final drive requires a relatively full set of specialised tools, not to mention a clean working area, I'm going to send these units out for some professional love.

I'm pretty tight on funds, but obviously want the job done right, so can any of you wiser members point me in the direction of an Australian re-builder (preferably somewhere in or around Melbourne), who can do the job right first time?

Cheers, Alex.