Polishing a Turd (K75S)

Bit of an intro:

About this time last year I sold a 1989 K75C that I'd owned for about six years. I bought it as a hack for the two days a week commute that I was doing at that time. It had been taken in p-ex by my local BMW dealer and I realised that the trade wouldn't offer much for it, that it would probably be broken for spares so I made a daft offer that was accepted.

After a few years I decided to tidy it up and enjoyed doing so. Then last year I reasoned that as I no longer had a commute, I could live with just my long-term (bought new in 2004) R1150GSA.

Earlier this year I was diagnosed with something unpleasant and realised that my days of loading-up the GSA and heading off for months was over. That bike had taken me on many long distance adventures, it was set-up to do exactly that and I couldn't bring myself to keep it just for the restricted distances that I'll now be covering (mainly because each time I got on it, I just didn't want to stop).

I kicked myself that I'd sold the K75 but after selling the GSA too I kept an eye open for a likely replacement.

A couple of months ago I spotted a likely bike on ebay. It was listed as an 86 model that had spent most of its life in Germany and then been imported (privately) into the UK in 2010. The equipment level was good; optional belly-pan, engine protection bars (unusual combination with the belly-pan but the latter was modified to allow them to be fitted), heated grips, 22 litre top-box, panniers (the last version of the Motocases with the scuff protectors and outward facing locks, keyed to match the ignition), RT twin horns and two almost new pannier inner-bags.

The mileage was sub-60K and supplied with the original kph speedo unit.

As far as photos permit (the bike was too far away to view), it looked pretty sound. Certainly not the "immaculate" that it was described as but a good basis for cleaning and tidying.

The downside was that it was advertised as "brown" in colour and the photos certainly represented a turd brown hue.

I decided that it was worth the risk and purchased the bike. It immediately became the "Two-wheeled Turd" in my mind.

Once I got to see it in real life I realised that contrary to the old adage, photos do lie. The colour is more of an olive-green than brown and the paint code reveals it to be Onyx-black metallic.

Here it is as I got it:



It was all there but the bike was cosmetically challenged, mainly it has to be said because it wasn't very clean. Someone had put a light coat of thin, dark paint over the front of the belly-pan and the lower edges of the fairing (seen here as a dull finish);



With some fuel added, I took it out for a quick ride to see what worked and what didn't. Everything seemed to work, the clutch needed adjustment and the higher speed handling didn't seem as good as I remembered my 75C being. I put that down to the tyres not worn out but possibly a characteristic of the Bridgestones (that I've no experience of). The rear suspension seemed a bit tired.

So, as in the title, I decided I see if it was possible to polish a 'turd'.

I began by removing the plastics and giving the hidden parts a good clean;





The mesh panels were removed and cleaned of surface corrosion before giving them a squirt of black enamel;



With the panels off;



I gave the paint a T-Cut and polish. The T-Cut soon removed the dull coating and revealed that the areas were pretty badly chipped, some areas that had been treated to touch-in attempts and even local blow-over (that didn't quite match the original);





They will do for now as I need to put some more miles on the bike to work out what needs to be done before worrying too much about the cosmetics.

The (replacement mph) speedometer was missing the two little black covers for the clock adjuster. A bit of black insulating tape tried manfully (and failed) to keep moisture out. It was a pretty simple operation to swap the part from the original kph unit;



While it was apart, I repeated a belt and braces fix I did on the 75C by putting a new bead of silicone sealer around the inside of the cover;



I also renewed the sealing O-ring as they are not expensive.

The bike looked somewhat forlorn sat on the lift;



Bridging the fan relay showed that the fan wasn't working (a common K-Series complaint). I whipped the radiator out (it could do with flushing anyway) and investigated the fan motor;



It was pharked. Completely solid. I did manage to free it but not enough to resurrect it (Lazarus it ain't).

Good old ebay soon produced a second-hand one at less than half the price of a new one.



While I had the cooling system apart, I rooted through my box of "bits that I really should chuck-out but that might one day prove useful" to find a piece of suitable clear pipe to replace the header-tank sight-tube;



Along with the fan, it's always wise to check the alternator drive cush-rubbers on the K-Series. It's a simple enough job;



I was just congratulating myself on having caught them as they were beginning to break-up when as I removed them there was a tinkling sound;



as the two broken drive blades fell out. Still, not a big deal. A replacement drive is only £8 here.



My rides to date had revealed a propensity for the bike to pop and bang on the over-run. In my experience with these machines, that and 'gold' patches on the silencer usually mean that it's sucking-in air somewhere. Off with the silencer, clean-up and re-spray the heat-shield. Then clean off the 'gold' (Wonder Wheels aluminium wheel cleaner is good for that but nothing else as it's too acidic for wheels really), clean the headers to silencer joint and re-seal it.

I took the rear wheel off for a proper clean while I was at it. The black finished wheels do stand-up to the ravages of time better than the silver finished ones;



The next thing was an oil and filter service including fork oil (just for peace of mind);



Then it was back together for a longer ride before decisions about what to attend to next.

I joined a friend for a weekend away. The outward leg was uneventful and the bike seemed okay. The homeward journey was a bit more eventful however. The journey out was on what we call in the UK "A class" roads: national speed limit roads, mainly single carriageway. Homeward was mainly via faster dual-carriageways. I was finding that anything over 80mph and the bike wandered quite alarmingly. Not shaking its head, not feeling difficult to steer but impossible to keep on a line through a fast sweeping bend.

I tried varying the tyre pressures to no avail. The steering felt fine, no obvious notchiness and not too loose or too tight.

So back home there was nothing for it but to have a look.



There was some brinelling of the bearing shells but not enough to cause the problem.

Next was the fluidbloc steering damper. For those who are not familiar with K75 models, the damper is a nylon (type) collar that sits in the headstock, held by two pointed grub-screws and is coated with a special grease that grips the steering stem.

Well it would appear that the bike has been stood for a while (possibly during its life in Germany) and the damper had seized to the stem. To free the steering, someone had forced/yanked the handle bars from lock to lock. This hadn't freed the damper's grip on the steering stem but it had rotated inside the headstock tearing two cuts in the fluidbloc damper body;



BMW used to sell the grease for the damper but now only the damper is available (pre-greased). Again, it's not expensive (under £20) but it did take ten days for one to arrive. Oh well. I can get on with some cosmetics while waiting.

First though, I ordered some new bearings and stainless brake hoses;



While waiting for the parts to arrive, I attended to the scruffy fork lowers and fork brace with a re-spray and cleaned/serviced the front callipers;



The battery tray and strap were also cleaned and painted;





The back end of the frame on these bikes can suffer because it's virtually unseen sandwiched between the mudguard and the rear seat unit. This one wasn't too bad (reassuringly as it underlines my impression that the bike has not had a hard life);



Cleaned and re-sprayed;



The frame generally was in great shape just dull and dirty. I took the opportunity to give it a clean and a coat of quality polish as protection;



I wasn't at all happy with the RT horns being hung on the belly-pan upper mount so with some fiddling and fettling I managed to accommodate them inside the upper fairing by using the two threaded holes in the lower triple clamp that usually mount the headlamp on 'naked' models. I only had to trim a small amount off one trumpet to ensure that nothing fouled on full lock.



Good old toothpaste polished-out all but the very deepest scratches on the screen (leaves it minty fresh too ).



The new and modified with an aluminium outer, fluidbloc arrived;



Time enough to attend to the slightly scruffy cam and crankcase covers;



Prepared;



First coat;



Removing the masking after final coats have dried;



Back on but needing a couple of heat cycles before polishing and detailing (this photo also highlights the poor paint finish on the belly-pan);



Right. Time to nail it all back together and see if the new bearings and steering damper have solved the problem. So, a sunny early morning ride up over Dartmoor;



Not much about as I pass Dartmoor prison;



Not the best view of HMP Dartmoor but it is there;



Then down to Dartmeet, onwards to the coast for a quick stop at Dartmouth;



It's so early that the sea mist hasn't burned off yet;



Back westwards along the coast and another stop, this time at Slapton and the memorial to the US servicemen killed here during Operation Tiger (google if you don't know the story):



Just along the coast (still misty) at Torcross is a Sherman DD that was raised from the seabed in the 1980's and now stands as a reminder of the sacrifices made here by young US men in the preparations for D-Day.



Back home (via Salcombe to pick up a brace of kippers for my breakfast) I decide that I've preloaded the new bearings a little too much as the bike is tipping into low speed corners a bit. A few tweaks (after breakfast) and another quick ride confirms the adjustment is now okay. The high(er) speed handling is now nearly as it should be. I suspect that a tired rear shock is now responsible for the occasional waywardness.

The clutch adjustment seems to have improved things but I suspect that the clutch is contaminated. Each time I ride the bike I find that wiping a finger over the joint between the bell-housing and the gearbox leaves a dark line of grease/oil on my fingertip.

Now either someone has been a bit over enthusiastic with spline lube (and as it wasn't owned by an inmate here, I doubt that ) or the output/balancer shaft seal is weeping. I'd spotted that a UK BMW part specialist (Motobins) had a special offer on K75 clutch kits for only £41.50. It's a no brainer really:



Well I'll be blowed. It was an over abundance of spline lube! As I had a new seal I bunged it in anyway;



Then fitted the new clutch;



With the gearbox, swing-arm and final drive off, I had though about doing what I did on my K75 and paint them black but as they weren't too badly marked, I gave them a clean-up with my patented method;





The swing-arm bearings are fine, just a re-grease will do but as always when doing this sort of thing there's always something that needs replacement. In this case it's the clutch actuating arm cover (split) and one pivot pin is cross threaded. So while waiting for these I kept an eye on ebay for a replacement main-stand.

Duck of this parish swapped the older version on his K75F for the later "two-footed" version and I had long considered this a worthwhile modification. The older "umbrella handle" type is prone to rusting from the inside out with the imagined consequences.

I was lucky and found one. A complete assembly with sub-frame and side-stand.

Odd shaped package courtesy of Royal Mail;



Grubby and bodged with Allen-head screws instead of the counter-sunk versions;





Stripped down, I selected the better parts (the later main-stand swivel bushes have two O-rings to retain the grease and they are longer as the stand has beefier hinge tubes);



The later type stand prepared for paint;



Painted and reassembled ready for re-installing;



The nice people at Real Engineering, in exchange for some of Her Majesties finest Pounds Sterling, sent me this;



They don't make suspension for anything but K-Series bikes having spent a lot of time working with owners on road and track to come-up with units that suit the bike (and progressive fork springs but I'll wait to see what effect the shock has before doing that).



Having used Ohlins for years on other bikes, I'm looking forward to seeing how this compares.

Well that's it for now. I have decided to re-spray the fairing and the belly-pan as I just can't live with the state of it. Years ago you used to be able to buy the paint from BMW. I went to my local dealership and tried to order sufficient 622 but was told that they are not allowed to sell it any more. :huh

"It's the EU Guv. They won't let us sell you it because of the solvents. Nasty stuff you know."

Bollocks! It's because BMW want me to pay them to paint it. I've tried sourcing the paint elsewhere to no avail so they've won and on Monday I'll be delivering the panels devoid of all fixings for them to re-paint. Truth be told, it's not as pricey as I'd thought it might be and it had better match!

To be continued................

.

42UKP for a clutch kit!?!?!?!?! Buy ten of those things next time you have the chance.

Great refurb!!

They probably ship to the USA and even if the shipping is pricey, at that price it's likely to still represent a saving.

http://www.motobins.co.uk/bmw-parts.php?model=K Series

Scroll down to Special Offers.

Nice job!

Good stuff!

That's a really nice TURD!!!!!

Great looking bike, that little bit of cleanup looks fantastic!!

Gearbox re-fitted along with the re-furbished main-stand. The alternator and starter are back in;



Then the swing-arm, shaft, final drive and new shock loosely reconnected;



Tomorrow, the fairing upper panels, the belly-pan and radiator panel go to the body-shop for re-spraying.

Inspiring.

Might have to wash my bike today.

Am curious as to what the handle A. T. T-W stands for.

And if you could possibly supply the link for the Real Engineering folks, I'd be grateful.

Google just keeps on spitting up an escalator repair company. :huh

See my sig line.

Sorry to give you duff information, I left the 'm' off the end.

http://www.realmengineering.com/page15.html

Bolted it all together properly;



Adjusted the new clutch and ran it through the gears.

I'm looking forward to trying out the new rear suspension but the paint-shop seems to be taking their time re-painting the fairing and belly-pan.

So to fill-in the time, I stripped the stone chipped engine protection bars and treated them to a new coat of paint;

Well done! An '88 K75S was my second BMW, and I will always have a soft spot for that bike. I see them on Craigslist every so often and get the itch to get another one.

Excellent work! Its always refreshing to see a person invest the time and effort to refurbish a bike. I have done a few myself, and it is very satisfying to feel and see the rewards of a bike that is well sorted.
Thanks for the virtual tour of the entire process!

Great work!

I have had a softspot for the K75S since reading comparos in magazines against the VFR750 back in the very early 90's. This was when I first started riding streetbikes, and I always seem to lust after bikes I wanted when I was 18.
Great work. I'd love to find a nice K75S in red with hard luggage someday.

You should put up some good photos of the finished work.

Well with time on my hands and between watching the home team do well in the Olympics, I stripped the stone-chipped engine protection bars before giving them a squirt of paint;



Being not too happy with the finish on the fork brace, I gave that another squirt (after suitable rubbing down etc) of some spare BMW Cosmos Black metallic I happened to have kicking around;



I even gave the water pump and timing chain covers another scrub, this time buffing it up with a coat of polish. They really could do with a re-spray but that can wait for some time in the future;



The re-sprayed fairing panels were collected this morning and I got them home without doing any damage;



Among a collection of odd washers I found some strange, slightly domed and cushioned with dense foam on the rear. I thought that these would be ideal for the upper fixings to stop the chaffing of the plastic that has occurred over the years.



I've no idea what they were intended for but whatever it was I obviously never fitted them.

With the belly-pan reassembled and the fixings jiggled back to where the best clearance is to be found, I added a couple of strips of helicopter tape to the leading edge to provide some protection from stone chips.



So then it was out to give it a shake down;



The new rear suspension needs some more miles before I start fiddling with the settings but even set at the softest to bed in, it feels so much better than the original tired BMW unit.

The new clutch is working fine, I just need to make a final adjustment to the actuating arm and cable. It's really nice and light now that everything has been cleaned and lubed.

Time to get out and enjoy it.



It has scrubbed up well for a Turd coloured old nail purchased unseen via ebay. The bike and all the work owes me less than £2,200.

Looking awesome