I've been splitting my time between the house and the K75, with the house winning in terms of percentage of effort but I'm heading down into the garage in the evenings to get on with the bike.
I have to say that after hankering for my own garage again after so many years without, I still get a huge buzz being able to unwind in my favourite space. Better yet, as the garage is integral, my usual first thing in the morning routine is to wander down there with my coffee and check-over what I've done the previous evening.
There has been a lot of preparation going on. All very repetitive and not particularly exciting to witness. Some reassembly work, such as the forks, putting the re-painted engine covers back on and feeding the wiring-loom back through its various routes.
The steering-head was bagged and spent a night in the freezer. With the new dust-cap on, I heated the new bearing and slipped it onto the very cold head-stock.
The bearing shells (top & bottom) were tapped into place using the old ones as guides.
Then the steering-head assembly was reassembled.
There had been some delay caused by the replacement fork leg dust-caps being in short supply. Oddly, BMW didn't seem to have any of these anywhere in their system and it took a month to track some down.
The new fork seals and spring-clips were easily sourced however.
I could at least reassemble the forks and fill them with new oil and offer them up to the steering yokes (temporarily) to align the yokes (you can see in this photo that the dust caps are still missing).
While waiting for the parts, I re-fitted the water-pump and timing chain front covers.
As you can see, I've raided my supply of Stainless Steel fasteners. The mating surfaces of both these covers have no gasket. Both were joined using a suitable jointing compound and then carefully torqued to their very low values.
The dust-caps finally turned-up, so I was able to slip the forks back out, add the caps and then start putting the handle-bars back in place.
Putting the cam and crankcase covers back was next. These have re-usable rubber gaskets but still are factory fitted with a jointing compound. When cleaning up the two surfaces, I found traces of an adhesive on the underside, in the corners of both covers.
I soon found out why it was there.
The gaskets are very slightly under-sized to provide some tension in their respective recesses. This small amount of tension makes fitting the covers very difficult as the gasket pulls out, even with the sticky jointing compound applied.
I used a thin, impact adhesive that was compatible with both types of material, fitted the gasket to the covers and allowed it to cure before applying the sealer and offering the covers up.
Again, I carefully torqued the cover bolts (new Stainless Steel) and making sure that the gaskets didn't pinch.
Purists may note that I've not ground the raised sections back to bare metal. Later K-Series had all-black covers and the bare aluminium is only going to be a pain to keep clean.
Nor, you will notice, have I done much about the sump. I may drop this in due course and give it the same treatment as the other parts. In the short term it doesn't matter that much as the second-hand 75S lower fairing (belly-pan) covers it. This is after-all just a tart-up and not a full blown restoration!
Getting the radiator hose out of the crankcase cover after all the years was hard work. The hose (like the others) is in good condition, no signs of perishing etc. When it came to re-fitting the hose, I used some BMW door rubber/window seal gunk designed to keep such items soft and flexible (I was given the stuff when a 7-Series I then owned developed squeaky window rubbers). It comes in a tube and is very handy. A small amount rubbed into rubber is quickly absorbed and keeps it from going brittle.
It also helped to lubricate its passage back into the crankcase cover.
Lately I have been attending to some of the other components that need cleaning and refurbishing.
Here are the screen support rods and the clamps that fit to the upper fork tubes.
The rear carrier has been cleaned of the old and flaking powder-coat, ready for re-spraying with Hammerite Smooth, satin black.
I whipped the tyre off the front rim. If you've been following this blog, you may recall that the wheels are odd colours. They both should be black but the front has been replaced at some stage with a silver one.
With the tyre off, I was going to rub down the wheel and re-spray it but I discovered that it had been powder-coated. Very, very heavily too. The powder coat chipped off in chunks. Removing it by hand would take forever so I dropped it off for stripping and re-coating.
It will be re-coated in silver. At the time of writing, the job's done but I haven't been up to Okehampton to collect it yet.
I really wanted to re-spray it black to match the rear wheel. When a suitable front wheel popped-up on eBay, I snapped it up. This wheel is in good straight condition. I've started preparing it for painting but I'll hold off until I collect the original one. I want to see what the finish is like. If it's good, I may sell the wheel on, or use it. In either case, I can either re-spray the eBay wheel black and use it myself, or re-spray it silver and put it on eBay (with it re-sprayed, I should cover the cost of it and the powder-coat).
I checked the brake-disc wear with a micrometer. They are both well within specification. The carriers were pretty tatty (powder-coat again). Two of the carrier screws were solid and the hex-key heads rounded out even after plenty of heat was applied. Using the Star-Key fix, I got them out without having to resort to drilling.
The discs were just treated to a clean (they're after-market Grimeca Stainless Steel items) and the carriers were stripped of their powder-coat by a liberal application of Nitromors. Then it was a re-spray with Hammerite smooth satin black.
The seat has a split at the leading edge. I'd thought about replacing the cover myself but as it's the 'low' seat and is deeply dished, the cover isn't the same as the standard seat. No-one seems to stock the low version as just a replacement cover, only the whole seat.
Fortunately, I know a company that can re-cover it. Autotrim in Ivybridge is owned and run by Ian Roper, someone whose work I've known for years. Ian also pointed out that trying to remove the old cover that's bonded to the foam on a seat so old, usually results in the foam being ripped apart. I was happy to leave the seat with him and he'll re-cover it.
I said at the start that there's been a lot of repetitive preparation stuff. Well, owing to funds being tight and it has to be said, the satisfaction of doing it myself, the body parts will be resprayed by me.
I still don't know for certain what colour I'll finish it in. My instinct is to go for a gun-metal metallic grey (like my old K100RT) but I'm also leaning towards keeping it the original white. The two benefits of the latter are that I won't have to notify the a change of colour and a solid colour is easier to apply than a metallic.
In either case, the parts all need to be prepared. That's rubbing down, repair (where required), priming, applying stopper to local irregularities, rubbing down again and further primer coats followed by a contour-coat, rubbing back yet again until the surface is ready for the colour coats.
Some parts, such as the headlamp cowl, the two-part front mudguard and the two-part radiator shroud are all flexible plastics. These need to be primed with a special paint that contains a plasticiser to prevent it cracking or splitting.
The 75S belly-pan is second-hand. It's been a bit knocked about in its life and the right-hand half has some damage.
I did fit it and ran the bike for a while with it in its odd colour mix just to be certain that it stayed put and didn't fall apart.
After repairing the major damage, it was rubbed-down and I gave it a thin coat of primer.
This highlighted surface imperfections. These were given a thin application of filler-stopper;
Then the parts were flatted back again:
And another primer coat applied:
This revealed a few areas that need more stopper:
This will be flatted back again and if it appears good enough I'll then blow over a thin colour coat. This in turn will be rubbed back. The idea is that it should leave just primer. Areas that still have the thin colour coat are 'low' and need stopper, areas that reveal the original colour scheme are 'high' and have to be rubbed down to the level of the surrounding area.
This process is not so important on parts not seen close-up but the tank especially needs to be right. It's all very slow but the final colour coats are easy to do. How good it all looks is down to the amount of care and detail in the preparation.
Other parts in various stages:
The lower half of the rear seat surround, the base, is black. The rear indicator housings are plastic. These too are black and at first I tried to remove the paint on them. The plastic will polish-up nicely but the paint couldn't be removed entirely.
I decided that they could be the same satin black as the seat surround base.
Lots still to do. I hope to have the seat and the front wheel back this week. I've got to get the GSA it's annual test soon and you may have noticed a strange item in the background in one or two photos. I have added a Suzuki AN400 Burgman to my stable. Yes. A scooter! I may even do a write-up on that at some stage. It's a hoot to ride. It goes very well (a bit squirrely at near 90mph. Must be the small wheels) and has good carrying capacity. It really suits my living back in the city. I might whip the exhaust off it once I can wheel the 75 about again (it's a bit crappy and could do with a clean-up under the plastics).
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