Author Topic: BMW K75RT Ultima Restoration  (Read 5063 times)

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 45
BMW K75RT Ultima Restoration: Seat Lock
« Reply #50 on: October 25, 2018, 01:53:32 PM »
As I was working on the back end, the seat lock was next in line, so that was pulled out of the box and put on the bench and stripped down ...



... to allow the parts to be cleaned up with Muc-Off motorcycle cleaner and the helmet lock catch polished up. This catch did show some corrosion on the chome plate, but it wasn't significant enough at this stage to justify replacement, so just the cleaning for this time.

The smooth head square cap bolts had previously been badly painted, so this was stripped off and the heads repainted with layers of Autotek Etch Primer, Halfords Gloss Black Enamel and Halfords Clear Enamel Lacquer before being allowed to cure.

The fittings were bought back together...



... before the lock unit was offered up and mounted to the bike...



... with the helmet catch and the seat lock mechanisms greased as well as the helmet catch with WD-40'ed return spring added to complete the job.

As always, if you'd like further details, please see motorcycleprojects.wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 45
BMW K75RT Ultima Restoration: Front Brake
« Reply #51 on: November 10, 2018, 01:44:26 PM »
With the back end of the bike starting to look good, the last of the systems running the length of the bike is the front brakes.

But, as the handlebars are not ready, this bit will be left for now.

So, everything was pulled together and the order of work decided, starting with the brake calipers, which were pulled out...



... the caps popped off and the pad pins drifted out and the pinch bolts, with a fair amount of effort, unwound...



... and put in the metal recycling box, these are definitely going to be replaced!

The ABS sensor was the next bit to take off, did it want to play ball? Did it hell! So, after heating and penetrating oil the damn thing still wouldn't budge ... so drilling out is the way forward to reveal some corrosion welding the bolts into place.

The sensor was also corroded in, meaning this needed to be wedged out with a screwdriver...



... to reveal the size of the tidy-up job here! The remaining studs were punched and drilled out to 5mm before a M6 tap was wound through to allow the sensor to be reattached later.

From riding the bike to the workshop, I know the brakes are good, so there is no need to go any deeper than this, so everything for each caliper was laid out and the halves of each caliper cleaned up, showing just how bad the cosmetic condition of the caliper was...



... given this condition, the paintwork was scuffed up, dust seals removed, mating faces masked up and the pistons masked up before building up thin coats of K2 Gloss Black Brake Caliper paint giving this plenty of time to cure (about 3 weeks while I was away for work) , before the o-ring was replace and both halves bolted back together, allowing the other bits to be lined up for cleaning and refitting...



... which went without incident...



... ready for the calipers to be reinstalled on the bike...



... allowing the pinch bolts to be torqued up (not that I could find a setting, so whatever felt right really - if there is any evidence of leaking when I bleed these, they'll be nipped up) and finishing the calipers, although the mounts have not been tightened as these will have to be moved to allow the front wheel to be removed for sorting later.

It's worth nothing here that due to high tensile strength bolts being removed, there were replaced with the same specification and not straight stainless steel bolts.

Next were the 2 flexible lines in the system, both of which showed corrosion on the ends...



... so both of the lines had both ends fitted with bolts and washers to protect the mating faces and the rubber portions masked off, allowing the build up of thin coats of Motip Silver Brake Caliper paint...



... and allowed to cure, before being put aside until the rest of the system is ready to be fitted.

Next on the list was the ABS pump, which was in a bit of a sorry state...



... so this was taken back with a wire wheel attachment on a drill to remove the loose material, but I found so much under-paint corrosion that across the majority of the pump it needed to be taken back to bare metal before the cable and brake fluid channels were masked off and the body coated with Autotek Etch Primer, Halfords Gloss Black Enamel and Halfords Clear Lacquer Enamel, before being set aside to cure and allow it to be mounted...



... complete with bleed nipple.

The final target for cleaning up were the fixed lines, so these were put on the bench, cleaned up and laid out on the bike...



... and the scale of the task dawn on me, I should have run these lines before I fitted the wiring loom back in, this will require a lot of wiggling and swearing!

So, the lines were fed through from the front of the bike, wiggling, shoving, pushing, adjusting and pulling one of the lines at a time until both were fed through and bolted into the ABS pump. I must admit, it would be so much easier if I'd not had the fusebox in at the time.

But it allowed the fixed lines for the calipers to be reinstalled alongside the flexible lines...



... before all the fittings were torqued down.

So the last bit to do is the earthing lead on the ABS pump, which had corroded through and dropped off as it was taken off the bike. But a new connector was found for the end, the wire was stripped back, continuity checked, new end attached, continuity checked again and bolted between the ABS pump and onto the top bolt of the footrest, between the plate and the gearbox.

Finally the continuity was checked again...



... and found to be good - finishing that job, with the master cylinder being completed as part of the handlebars and bleeding down as part of the commissioning later.

As always, if you'd like further details, please see motorcycleprojects.wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 45
BMW K75RT Ultima Restoration: Radiator & Cooling
« Reply #52 on: November 20, 2018, 05:43:20 AM »
Next in line is the cooling system, given the water pump has previously been done, that means the radiator and hoses, so that was popped on the bench...



...the easiest bit to remove is the stub pipe which fits onto the crank case, so that was removed, the temperature sensor removed and the pipe popped into the vice...



... which was cleaned up with a wire brush attachment on a drill and the stub pipe masked up before being given a few coats of Plastikote Aluminium Engine Enamel, allowed to dry and the masking removed...



... and set aside to cure.

So, back to the radiator assembly, the hoses were removed and put to one side, allowing direct access to the fan, which was definitely 'firmly' attached - with 2 seized bolts which were cleaned up with a wire brush and the edges of the heads cleared of corrosion with a pick tool before being treated with penetrating fluid on front and rear...



... and left to soak for a while, say time enough for a couple of cups of tea!

The bolts were tried again, but no movement was forthcoming. So a little heat was added to gently warm the bolts and the clips they bolt into, gentle because the proximity to the radiator...



... which, after a fair amount of time, allowed the bolt to be eased out and left me with a loose fan, but it needed some cleaning up after that!

And onto sorting out the state of the radiator parts, starting with the radiator itself, which wasn't in the best of conditions cosmetically...



... but the cooling surfaces and internal pipe work all looked good and there were no leaks on the ride home.

As nothing was fundamentally wrong, the radiator was cleaned with a rag and WD-40, the blistered and flaking paint removed with the help of a wire brush and a pointy tool, taking care not to damage the internals before being painted with cylinder block paint...



... and set aside to cure off.

While waiting for that, the thermostat and cap were next up and as these are known to be good, these were cleaned up and the thermostat replaced in the radiator...



... followed by the cap returning the radiator to one piece.

Next up is the bottom mount which was cleaned up with a wire brush drill attachment and the elbow grease of a good friend, so it was ready for painting.

The mount was treated to layers of Autotek Etch Primer, Halfords Gloss Black Enamel and Halfords Clear Enamel Lacquer and left to cure off.

Meanwhile, attention was turned to the cooling fan, which was tested for function by jumping it across the battery...



... and it worked faultlessly.

The balance weight was removed, the location marked and the weight was cleaned up before a couple of coats of Hammerite Smooth Silver and set aside to cure.

The fan itself was cleaned up with a rag and WD-40 and the balance weight replaced...



... meaning the fan is done!

The stub pipe was refitted with the temperature sensor, with the copper washer replaced and the threads smeared with gasket sealant and the unit was fitted with a new o-ring and mounted onto the crankcase so it's ready for the rest of the cooling system.

The radiator assembly was put back together and loosely mounted on it's bottom mounts...



... as an offering up to make sure everything is where it needs to be (and proving I may need to visit the routing of the front brake fixed pipework, but I'll sort that later).

With that done, all the hoses were pulled together and cleaned up with WD-40 before the hoses on the stub pipe were reconnected...



... before the radiator could be remounted and the remainder of the hoses reconnected.

Next step was the expansion bottle, which was grabbed from the ever-shrinking parts pile which was cleaned up and mounted back into the frame...



... which then allowed the air intake ducting to be replaced...



... finishing both the radiator work and the airbox.

As usual, the system will be commissioned later.

As always, if you'd like further details, please see motorcycleprojects.wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 45
BMW K75RT Ultima Restoration: Bodywork Mounts
« Reply #53 on: December 09, 2018, 03:27:51 AM »
As some of the electricals and control cables need to be run through the front bodywork mounting, it seemed reasonable to the mounts done next.

Starting with the front mount, this was pulled together and the rust stripped off, with the remaining paint prepared by roughing up with 600 grit wet & dry paper...



... before Autotek Etch Primer was applied before coats of Hycote Gloss Black and Halfords Clear Enamel Lacquer and set aside to cure.

Once cured, it was bolted back onto the headstock...



... allowing the rubber grommets to be refitted ready and cables properly run.

Onto the remaining bodywork mounts, these were grabbed together...



... and had all surface corrosion and dirt removed with a wire brush drill attachment these were then treated to a good number of coats of Hammerite Smooth Silver...



... and set aside to cure off.

The mounts were then rebuilt with the original bolts, rubber grommets and mushroom washers before being mounted onto the fixing points on the bike...



... with one 1 mount requiring the radiator filler cap to be moved to allow it to fit.

To finish the job, the relay mounted on the front bracket was cleaned up, refitted and connected up to the wiring loom.

Onto the next job!

As always, if you'd like further details, please see motorcycleprojects.wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline natalena

  • ^ Proficient Motobricker
  • Posts: 163
Re: BMW K75RT Ultima Restoration
« Reply #54 on: December 09, 2018, 08:13:55 AM »
Fantastic, methodical progress. Well done, and has inspired me to work on some fiddly bits as the temps drop below 3c here (seat lock assembly for certain.) Cheers
  • East of Joshua Tree
  • 1987 K75s #0919
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Offline Barry in IN

  • ^ Proficient Motobricker
  • Posts: 136
Re: BMW K75RT Ultima Restoration
« Reply #55 on: December 09, 2018, 01:22:59 PM »
This is great to see.  It’s the kind of “build” I can really appreciate. 
  • Indiana
  • 1992 K75S Lili Von Shtuppe
A pox on cafe “builders”
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Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 45
BMW K75RT Ultima Restoration: Handlebars & Controls
« Reply #56 on: January 01, 2019, 10:41:10 AM »
Getting the bike on and off the lift is a bit of a pain at the moment, so handlebars should help with that.

These were grabbed and popped on the bench and stripped to the bare handlebars...



... from here the bars were stripped back to bare metal, due to the rust seen on the clutch lever side of the handlebars, before being treated to Autotek Etch Primer, Halfords Gloss Black Enamel and Halfords Clear Enamel Lacquer and allowed to cure.

Once cured off, a length of fairly stiff electrical cable was fed from the centre hole in the handlebars to one end, before the remained was looped around the handlebars and then fed through to the other end...



.. to allow the cables for the heated grips to be pulled through later on.

This was then mounted onto the top yoke of the bike, adjusted (for now) and torqued down.

With that done onto the controls, which were popped onto the bench in turn and stripped down. The front brake master cylinder was inspected but it will stay in situ, rather than risking damage by stripping it down when I know it works well.

The adjustable parts, such as the front brake light grub screw were measured so that when these are replaced, they can accurately be reset and minor adjustment undertaken from there.

Once stripped down, this left me with 2 piles of bits...



... things that need cleaning and degreasing and those bits which are in good condition.

The bits that needed cleaning were soaked in Muc-Off Motorcycle Cleaner while the electrical items were tested for function and the screw threads cleaned up by running them through a dye.

With that done, and the parts continuing to soak, onto the electrical switchgrear elements of the handlebar controls...



... these are known to work, so no further stripping down required. But the controls were grubby, so using a rag with a small amount of WD-40 these were cleaned up. The thing that struck me here was that the markings on the controls were very faded, in no way a problem to function but gives me some research to do to see if these can be replaced.

Once done, the wiring for the controls was fed through the front of the bike and connected up ready for the remainder of the parts, once completed.

Next up was the central handlebar controls which were broken down into it's component parts...



... and the mount was cleaned up with WD-40 on a rag  leaving the next step as the ignition barrel.

On removal the tab retaining this dropped out, it would explain why the barrel was partially push back into the dash, so by using a hot knife this was plastic welded back on to the stump which allowed the barrel to be checked for electrical operation with a multimeter before being refitted into the housing.

Each of the switches on the housing was tested electrically and cleaned before being refitted into the housing.

The hazard light switch was found to have corroded electrical connections and a broken wire on further investigation the internal connections were also corroded...



... so these were cleaned up with a little sandpaper and electrical contact cleaner before the back of the switch was refitted.

The external connections were de-soldered, the wires stripped back to remove the corrosion and the contacts cleaned up with a wire brush. The wires were then soldered back onto the switch and tested and found to now be operational.

his allowed the central control panel to be rebuilt and bolted back onto the bike...



... allowing me to move onto the handlebar controls, which required the clutch sensor to be removed with a box spanner...



... unfortunately this did call for the cable to be cut, but this will be reconnected once everything was done.

With the control parts stripped (yes I gave in and removed the front brake master cylinder), soaked and degreased, the parts that then required painting were stripped using Rustoleum No.1 Green Paint Stripper before these were given coats of Autotek Etch Primer, Halfords Gloss Black Enamel and Halfords Clear Enamel Lacquer...



...and were allowed to cure off before reassembly commenced with both sets of controls being as built up as possible before even looking at the bike.

While everything was being added to the handlebars, the wires for the heated grips were taped to the wires that had been previously threaded through...



... allowing the wire to be pulled through to the exit hole in he centre of the handlebars, and the grip fitted to the bar...



... so the heated grip wiring could be soldered back together and connected up, alongside the wiring for the clutch, brake and sundry dash switches.

Following this, the choke, throttle and clutch lines were run and hooked up, just leaving the flexible front brake line, which was connected to the fixed line and connected up tot he master cylinder.

Things like the clutch adjustment and a decision on if I'm going to take a look at re-marking the handlebar controls will happen with the commissioning and finishing touches respectively.

As always, if you'd like further details, please see motorcycleprojects.wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 45
BMW K75RT Ultima Restoration: Clocks & Horns
« Reply #57 on: January 01, 2019, 10:50:49 AM »
With the front end taking shape slowly, various work commitments and seeing family slowing work down (but not is a bad way - just in case my wife reads this), it was time to move onto the clocks.

Thankfully I'd kept the clocks in one piece while the bike was disassembled, as I knew these worked and didn't suffer from fogging seen on some K75's, so a straight re-fit, happy times here! With a spring in my step, at the thought of an easy job, I grabbed the clocks and popped them on the bench giving the clear plastic a clean with a dry rag and the black plastic a wipe with a rag just dampened with WD-40, but something didn't look right...



... it seems when taking this off the bike, I flipped the bracket around and refitted it, so that was quickly rectified (still with a spring in my step!) before the bolt holes were cleared up with a bolt and the tired looking bots replaced with stainless steel upgrades.

But, I went to mount the clocks, something else didn't look right...



that rubber seal shouldn't look like that. So the back of the clocks were popped off to find that at some point in history the clocks had been apart (probably to replace a bulb), the seal had been allowed to fold over on refitting. This was straightened out and the back screwed back onto the clocks, finally now ready for bolting back onto the bike!

The clocks were offered up, wiring from the handlebar controls directed through the curve (but not the hole) in the bracket, and the electrical connector for the clocks pushed into place...



... and secured with a small bolt into the back of the housing.

Leaving the handlebar based items pretty much completed...



... until I change my mind about something anyway!

While I was on a roll, I grabbed the horns...



... and as these worked well before the bike was disassembled, they were cleaned up, bolted back into place and the wiring reattached...



... completing 2 jobs in one here.

As always, if you'd like further details, please see motorcycleprojects.wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

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