Author Topic: K75 Engine Swop  (Read 1323 times)

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
K75 Engine Swop
« on: September 10, 2018, 02:31:42 AM »
So - nearly there, so thought I'd post some pics of what an Engine swop involves - plenty of work, but doable at home and good a challenge in project management
! Engine popped so bought a 50k miles replacement " Here's hoping it fires up!

  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline Rcgreaves

  • ^ SuperNatural Motobricker
  • Posts: 519
Re: K75 Engine Swop
« Reply #1 on: September 10, 2018, 03:15:27 AM »
Very cool!

Carry on.....
  • Livingston, SW WI. USA-"With the good earth all around."
  • NEW 1995 K1100RS Red,1994 K75S Red,1985 GL1200A Goldwing Aspencade, dreaming of adding a sidecar to the mix in 2019
Doing “better than I deserve”

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6396
Re: K75 Engine Swop
« Reply #2 on: September 10, 2018, 09:07:20 AM »
I can envision clamoring here for the polka-dotted work-seat/footstool. Amazonians, take note!
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline herseyb

  • ^ Proficient Motobricker
  • Posts: 189
Re: K75 Engine Swop
« Reply #3 on: September 10, 2018, 03:02:28 PM »
Awesome - I picked up a spare k75 engine/rear and have been thinking about looking through it... 

Take lots of pictures for me!
  • Madison, Wi
  • '90 K75

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6396
Re: K75 Engine Swop
« Reply #4 on: September 10, 2018, 04:03:49 PM »
Awesome - I picked up a spare k75 engine/rear and have been thinking about looking through it... 
Learn to do that and the TSA will hire you on the spot. Good part-time work!
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #5 on: September 11, 2018, 07:28:59 AM »
Yep - last night put Injection back on and wired in Computer now that it's turning over again safely.
Couple of my sons mates - 3 in Total helped me move the Frame back onto the Bike...

Found a connection issue - fixed, though I think it's for the ABS which I removed including cutting out the Wiring Loom - that's 12 kilos and future trouble removed. Yes, I know - The one day it works, it'll save you... way over complicated for a 1991 Bike... ABS was working but couldn't be bothered with it for all the extra tech - removed both relays and Pipes front to back - leaves me needing a new Front Brake hose and Rear...

Found the Temp sensor in the old Engine and wired it in also last night...
Fitted Rad, Pipes and filled with Anti-freeze / Coolant mixture - here's hoping it doesn't find it's way into the Oil this time round.
Old Engine is sitting in the Corner, sulking, stripped to bits awaiting further investigation for those that read the sorry tail of it eating it's coolant.
Stripped Pump front and re-sealed with Silicone and re-fitted.

Most useful Tool - Wire Brush
- Jeez, 30 years of muck and crap on every bolt - wire brushed, stripped and cleaned every single nut and Bolt including Centre stand... treated myself to a new one this morning
Some more pics of Engine on Bench plus some others.
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #6 on: September 11, 2018, 07:37:57 AM »
Awesome - I picked up a spare k75 engine/rear and have been thinking about looking through it... 

Take lots of pictures for me!

It's fairly straightforward with a Dry Garage and Home Tools - Undo everything, wiring, cables, frame Pins - pull et Voila 2 big bits -

1. Bike Frame and Front - Fairly clean
2. Engine, Gearbox and Drive plus Rear Wheel - full of muck and crap from 30 years on the road and British Winters

- lots of buckets and boxes for bits and a Wire Brush and some Gunk / DeGreaser
- most time so far is all the cleaning and painting of the bits, plus pulling the frame off, then walking it back on.

On the home run now - hope pics are useful..
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #7 on: September 11, 2018, 07:47:12 AM »
Pump looked pretty good inside compared to the old unit on original engine.

Just waiting on replacement second user Downpipes / Manifold - old ones were shot when I pulled them off - all studs out easy enough though - new studs and exhaust nuts purchased.
New Oils this morning ready to fill Engine... Gearbox Oil and Final Drive

New and Old Pics...
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline Nine80seven

  • ^ Proficient Motobricker
  • Posts: 110
Re: K75 Engine Swop
« Reply #8 on: September 11, 2018, 10:30:24 AM »
Save all receipts in case DMV asks you for the motor number, as they did to me when I first purchased my current K.   

It's a 'reconstruction' thing.  Happened to me twice, once a reconstruction and once on a simple title transfer.  All the cars and bikes bought and sold over the years and never asked for engine number?  I asked why, they just repeated, go write engine number here, drawing a blank on the title. I did it and they said I had the wrong engine?  That one took five months to correct and never found out why?  And the bike had the original engine?  According to manufacture data anywho.  Two centavos, FWIW.
  • MN
  • 85 K100RS

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6396
Re: K75 Engine Swop
« Reply #9 on: September 11, 2018, 10:45:35 AM »
Save all receipts in case DMV asks you for the motor number, as they did to me when I first purchased my current K.
The Ministry of Transportation inspection in the UK is probably much worse than anything Minnesota has thought up, although I'm sure officials in MN are frying their brains in an effort.
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #10 on: September 12, 2018, 09:53:45 AM »
The Ministry of Transportation inspection in the UK is probably much worse than anything Minnesota has thought up, although I'm sure officials in MN are frying their brains in an effort.

Actually they are pretty easy over here, they don't check Engine numbers at testing time... only Chassis number to check it's the right Bike they are Testing... I can change number on log book though, good shout. UAE is harder than the UK in this respect... everything has to match, including Colour of Tank.
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #11 on: September 12, 2018, 09:54:54 AM »
Replacement Manifold arrived this morning, re-fitted Tank in readiness... should fit tonight and find some Fuel.. will report back or post another "Help" thread!!!
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #12 on: September 12, 2018, 05:11:25 PM »
Success - exhaust manifold and silencer on, couple of cranks, bit of choke and it starts and runs...
I put 10cc of Oil in each pot to seal it and seemed to do the trick... very pleased that this Engine is good - circa 54k miles on it...

Will try and upload the final start up Video and a link soon.
Meanwhile final Pic of re-build from earlier today - took maybe 40 hours in total... just the brakes to sort and then roadtest..
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline The Mighty Gryphon

  • ^ Quintessential Motobricker
  • Posts: 4402
Re: K75 Engine Swop
« Reply #13 on: September 12, 2018, 06:08:40 PM »
That came together very nicely.
  • In my garage in Marilla, NY
  • '94 K75RT Mystic Red, '91K100RS White/Blue
Current:
'94 K75RT "Ilsa, She Wolf of the SS"
'91 K100RS "Moby Brick Too

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #14 on: September 15, 2018, 09:13:12 AM »
That came together very nicely.

Thanks, and thanks for all your support on this forum. Very helpful to get advice from you...

Here's a couple of pics on my first ride out.
Connected brake lines last night and reverse bled with a Syringe, that worked well... runs a little ropey, not sure why but couple of pops... maybe needs timing sorting but overall revs well and goes OK. Won't tickover without a bit of throttle so any advice welcomed on what to tweak first to settle it down?

I know every nut, bolt and cranny now on this Bike and I'm glad I removed the ABS - looks cleaner too.

Note Gauges mounted on right hand side - work well - I'll make another post about this, but really easy for RT to Naked conversions like mine... even glow in the dark!
Enjoy!
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

Offline mw074

  • ^ Proficient Motobricker
  • Posts: 281
Re: K75 Engine Swop
« Reply #15 on: September 15, 2018, 11:43:23 AM »
Very nice. Wow is that license plate huge!
  • Michigan

Offline bluebossa

  • ^ Proficient Motobricker
  • Posts: 155
  • K75 and R65 Owner
Re: K75 Engine Swop
« Reply #16 on: September 16, 2018, 10:39:07 AM »
Very nice. Wow is that license plate huge!

Thanks - yeah think it's legal size here in UK...
  • UK
  • K75 RT
Current Bikes: K75(RT) in the UK (06/91), R65
Former Bikes:  R850R, K1100RS, Dnepr MT10-36
BMW R65 and K75 Blog

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