Author Topic: BMW K75RT Ultima Restoration  (Read 862 times)

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 10
BMW K75RT Ultima Restoration
« on: March 17, 2018, 02:34:29 PM »

Greetings  :mm ,


I have just moved on my last project and I would like to share with all of you my next project - a BMW K75RT Ultima.


As you may know, the Ultima is the final addition of these 3 cylinder engined motorbikes so beloved by police across the UK and Europe.


I picked this up from the father of a good friend, so I know the history and I know mechanically the bike is solid, so it is mainly cosmetic work I'm undertaking on this one.


For those of you interested, you can follow the progress of the restoration via MotorcycleProjects on Wordpress.com
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

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  • Posts: 10
Re: BMW K75RT Ultima Restoration
« Reply #1 on: March 17, 2018, 05:04:26 PM »
Looks like the link didn't work - here it is so you can go straight to it ... http://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: 10
Re: BMW K75RT Ultima Restoration
« Reply #2 on: March 17, 2018, 06:28:44 PM »
Good thing I'm much better with suck - squeeze - bang - blow than micro-processors!


Let's try the link again ... [size=78%]https://motorcycleprojects.wordpress.com[/size]
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 10
Re: BMW K75RT Ultima Restoration
« Reply #3 on: March 18, 2018, 06:17:16 AM »
The father of a good friend has been considering selling his bike for a while and wanted to ensure it would go to someone who appreciated it. After a few cups of coffee and conversations about the bike over more than a year, and knowing the bike is pretty much there mechanically, it felt right to buy the bike and bring it back up to 100% cosmetically.

After getting the bike home, the bike had the once over to see what needed doing. After going through the history of the bike, it looks like the bike has always had genuine parts, so this will be continued as much as possible.

The initial to do list consists of:
>Sticky Rear Brake Light Switch
>tragkorb Hinges Cracked
>Dashboard Light
>Corroded Brake Line Fittings

>Paint Damage on Engine, Gearbox, Frame, Fork Stantion and Bevel Box

>Paint Damage on Rear Wheel

>Paint Damage on Bodywork

>Bubbling RHS Fairing Pocket Cover
>Corroded Nuts & Bolts


I try to take my time over projects, with these usually taking 18 months plus - so please watch this space for updates.
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 4928
Re: BMW K75RT Ultima Restoration
« Reply #4 on: March 18, 2018, 06:59:02 AM »
Welcome, Wolly!

Your project is certain to be of interest here. Good luck with it.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline The Mighty Gryphon

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  • Posts: 3511
Re: BMW K75RT Ultima Restoration
« Reply #5 on: March 18, 2018, 10:50:42 AM »
Looking at your list it sounds like a fairly straightforward and very satisfying project ahead for you. 

I like replacing nasty looking fasteners with stainless steel.  A lot of them for stuff that isn't heavily stressed where the original is M5 or M6(fairing panels, timing chain cover, etc.) can be the cheaper grade.  Just remember to reduce the torque on them by about 10% and use copper anti-seize.  I get mine in bulk fairly cheaply on eBay, or you can buy a complete kit that has just what you need.

With the age of the bike, you might want to replace the original brake lines with stainless steel braided along with new fittings.  Most of the places that sell the lines include new fittings.

A good inspection of the fuel lines and breather hose is in order.  You might just want to plan on replacing them if they don't look almost new.

If you can, see if you can find some S-100 for cleaning parts.  I have found that it is a super quick way to remove a lot of old dirt and grime and bring parts back to looking almost new.  When I am doing work on a bike, as soon as I remove something it goes to the laundry and gets a cleaning before I do anything else.  It's so pleasant to handle and work on clean parts.

Good luck with your project. 
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '92K100RS White, '94 K75S Dakar Yellow
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'94 K75S "Cheetos"
'91 K100RS "Moby Brick Too

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 10
Re: BMW K75RT Ultima Restoration
« Reply #6 on: March 18, 2018, 10:58:23 AM »
Cheers for the advice Mighty Gryphon  :2thumbup: , it looks like we are thinking along the same lines regarding the brake lines, hoses and fixings.


I'll keep an eye out for S-100, I tend to clean parts before I do any work with them but if the S-100 can make cleaning easier, I'm all for it!
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline Wollyjumperuk

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  • Posts: 10
BMW K75RT Ultima: Bodywork Strip Down
« Reply #7 on: March 31, 2018, 02:09:25 AM »
With the bike safely in the garage and up on the ramp, it was time to remove the bodywork to see how bad the corrosion was on the frame, so see how far I'd have to get into the bike.


Starting from the back, all the parts were removed from the frame methodically, with all of the bolts replaced in the threads they came from ...

... all electrical connections marked before disconnection and photos taken of all the cable runs to ensure re-build as close as possible to original.


During the strip down only 2 fixings were so corroded that they had seized, unsurprisingly both of these were at the rear of the from, where these are directly exposed to the elements ...

... using PlusGas disassembly penetrant, a heat gun and (briefly) an impact driver, these were coaxed out - I can't stand sheered bolts and studs, so I tend to spend the time trying to coax these out. As you can see from the picture the corrosion to the back end of the frame was extensive, so I decided to remove the front fairings to see how far forward it goes and if I'd need to take the frame off the engine to sort the corrosion to my satisfaction.


The only challenge to removing the front fairing was getting the mirrors off the fairing. I did a fair amount of research into mirror removal, as the method to get these off seemed a bit brutal - at effectively hitting these with your palm from below, as hard as you can, to get these to 'pop off' ...

... in the end I used a large flat head screw-driver between the fairing and the mirror to 'pop' these off, fitting by fitting.


Following this the front end was pretty straight forward with all the fixings coming off cleanly, with no seized items at all and even a spare key fount cable-tied inside the front fairing! The nose fairing came off with the 6 bolts and the electrical connections were labelled and section taken off.
[/size]
I was expecting the corrosion to the rear, as the frame is really not protected from the dirt the rear wheel flings up, but there is evidence of corrosion all the way up to the front fairing sub-frame, not as bad as the rear of the bike, but enough to require the frame to come off of the engine to get it sorted.


For more information, please take a look at my bl[/size]og at https://motorcycleprojects.wordpress.com/
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 1612
Re: BMW K75RT Ultima: Bodywork Strip Down
« Reply #8 on: March 31, 2018, 04:58:58 PM »
The only challenge to removing the front fairing was getting the mirrors off the fairing. I did a fair amount of research into mirror removal, as the method to get these off seemed a bit brutal - at effectively hitting these with your palm from below, as hard as you can, to get these to 'pop off' ...

... in the end I used a large flat head screw-driver between the fairing and the mirror to 'pop' these off, fitting by fitting.
Don't sweat it.  These bikes are German. They appreciate a good slap now and then. :D
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/
2011 Moto Guzzi V7 Racer

Offline Wollyjumperuk

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  • Posts: 10
BMW K75RT Ultima: Frame & Engine Parting
« Reply #9 on: April 18, 2018, 05:57:10 PM »
With it clear that the frame of the bike was fairly corroded, it needed to come off to be sorted, so began the parting of the engine and the frame.


It started with an emptying of the coolant by disconnecting the hose at the lowest point and letting it drain before removing the radiator to reveal ...

... the corrosion at the front of the frame was worse than seen on the rest of the frame - supporting the decision to remove and treat the frame.


The brake system was bled down and the lines disconnected where they pass though the frame before the engine block was supported in preparation.


The front wheel was dropped out and the frame unbolted to allow the frame and forks to be removed in one section ...

... leaving the engine and transmission standing ...

... to be tackled next, alongside an oil leak from the rear of the gearbox, discovered just after the frame was released and removed.


For more information, please take a look at my bl[/size]og at https://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: 10
BMW K75RT Ultima: Engine & Transmission Disassembly
« Reply #10 on: May 02, 2018, 05:41:17 PM »
The starting point was removal of the rear wheel and draining the oil out of the rear bevel box as I am going to change it anyway – I might as well get it as light to handle as possible! And it was just as well, as the oil that came out did look a little past it’s best.
[/size][/color]Following this the rear bevel box was unbolted and eased off the end of the swingarm and the drive shaft connector, bearing and smooth operation checked and all found to be very good with no play, so no further disassembly at this time here.[/font]
[/size][/color]Following the bevel box, the next component forward was the swing arm, the 2 stub axles were removed and this was eased away from the gearbox and slid off the drive shaft. The swingarm needs a good clean before an inspection can be properly done, so that’s for later.[/font]
[/size][/color]With the removal of the swingarm, support of the motor was somewhat lacking, so a few wooded chocks were put in to aid the bottle jack and the main stand to maintain stability …[/font]
[/size][/color][/font]
[/size][/color]… this support would later be supplemented with a ratchet strap over the garage roof beam to give a little reassurance.[/font]
[/size][/color]Looking toward removing the gearbox unit, it was clear the only other parts needing removing at this time was the scrotator and the starter motor. These were both unbolted and eased out leaving a small pile of worn-off scrotator cush drive rubber, so this goes on the replacement list too.[/font]
[/size][/color]The remainder of the wiring loom, coil packs, airbox assembly and throttle bodies were taken off with little effort, leaving the injectors to be eased out followed by the manifold stubs and coolant post.[/font]
[/size][/color]Unfortunately, both the front manifold stub and coolant post had seized bolts, 3 in total one sheered stud could be wound out by locking 2 nuts together on the stud (thankfully the thread was OK), and the stud wound out after some gentle heating and constant, steady application of pressure on the lower nut against the lock nut …[/font]
[/size][/color][/font]
[/size][/color]… I was not quite so lucky with the other 2 studs. Here starts on-off work on these over a 2 week period.[/font]
[/size][/color]After many attempts to remove, , these were ground flush, drilled and tapped before the replacement bolt was run into the hole – success![/font]
[/size][/color]With the inlet manifold done, it was time to move onto extracting the gearbox. As this would mean turning the engine onto it’s leading face, the oil filter was drained (by punching 2 holes in it so it could drain) and the engine flipped the stands removed and the gearbox bolts undone. To aid things, a ratchet strap was threaded through the swingarm mounting holes and the slack taken up. The gearbox was tapped round with a rubber mallet to get it moving before the ratchet was used…[/font]
[/size][/color][/font]
[/size][/color]… to lift the gearbox away.[/font]
[/size][/color]The last part of the disassembly was the removal of the exhaust headers. So the engine was rolled so it was upside-down and the exhaust header studs given a coat of PlusGas and left to soak overnight.[/font]
[/size][/color]Once soaked, the nuts were heated up to expand them off the studs but they won’t budge and we’re rounded due to corrosion. A nut splitter was used to deform the nuts and provide something to grip on and an easy out socket used this worked with just a few nuts having to be beaten round.[/font]
[/size][/color]With that done, the major disassembly is complete… time to start the process of rebuilding![/font]
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline johnny

  • TrailBrakingThrottleWhacker
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  • Posts: 5905
  • Whacking...n...Chopping Sliding...n...High Siding
Re: BMW K75RT Ultima Restoration
« Reply #11 on: May 02, 2018, 08:30:28 PM »
greetings...

very interested in your renovation... however that is one f-ed up post... unreadable at best...

you outta getts some seperation in there...

j o
  • i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin...

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 10
Re: BMW K75RT Ultima Restoration
« Reply #12 on: May 03, 2018, 12:34:01 PM »
Yes, it is pretty shocking - unfortunately I failed to use the preview button and there does not seem to be a way to edit this once posted.


Just as well I'm better with metal than with silicone!


Please feel free to check out https://motorcycleprojects.wordpress.com/ for a cleaner version
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

Offline thecableguy

  • ^ Motobrick Curious
  • Posts: 108
Re: BMW K75RT Ultima Restoration
« Reply #13 on: May 03, 2018, 01:03:10 PM »
... there does not seem to be a way to edit this once posted.

Once you hit the magical number of posts you'll unlock the "Edit" feature.


(The number is 10. You're almost there...)
  • Madison, WI USA
  • 86 K100RT - Brünhild
...to make a long story short, use duct tape.

Offline Wollyjumperuk

  • Motobrick Curious
  • Posts: 10
BMW K75RT Ultima: Main & Side Stands
« Reply #14 on: May 12, 2018, 06:42:30 PM »
The stand assembly was clamped in the vice ready for the disassembly. Everything was undone and disassembled, the stubborn bolt was lubricated and heated and pressure kept on the bolt until it released.

All the loose bits were put in a bucket, part cleaner added and diluted and left the soak overnight. After soaking the water was definitely dirty and the parts vaguely cleaner!

With everything taken apart and spread out to check everything is here...

... and any parts damaged beyond use or repair were replaced.

The side stand - clutch interlock was particularly caked in road crud, so it went from fresh off the bike (top left) to being soaked in Muc-Off cleaner and being scrubbed (bottom left) degreased (bottom right) and polished up using Autosol Metal Polish, fine wire wool, soft cloth and a polishing mop on a drill (top right)...

... this was also done to the other required non-painted parts.

The stand mounting bracket and both stands were stripped back with a wire brush drill attachment removing all the old paint and corrosion before masking up, spring holders masked by using o-rings (as the springs will kill the paint anyway) and priming with 2 coats of Autotek Etch Primer, followed by 2 coats of Halfords Gloss Black Enamel (typically running out of paint half way through, so had to run and get some more) and finally 2 coats of Halfords Clear Enamel Lacquer. With 24 hours left between each change in paint and everything left to completely cure for a further week once completed.

Once cured, all the parts were pulled together and the stand assembly rebuilt...

... ready to be bolted back onto the gearbox.

N. B. The springs will be added once the stands are on the engine/transmission assembly for ease of leverage.
  • Fareham, Hampshire, UK
  • BMW K75RT Ultima
Wollyjumperuk
For more on my motorcycle projects - please see https://motorcycleprojects.wordpress.com

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