Author Topic: Need experianced eyes on a few pictures by my K75  (Read 4342 times)

Offline JoHo

  • Motobrick Curious
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Need experianced eyes on a few pictures by my K75
« on: April 17, 2019, 12:35:27 PM »
Hey guys.

I finally began tearing Down my 1987 K75C and i ran into a few Problems with tearing and stiff. Can I please get someone Who knows his stuff to take a look at these pictures and tell me if they need changing and so on?
  • Denmark
  • BMW K75 C 1987

Offline blackie1

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  • christchurch nz
Re: Need experianced eyes on a few pictures by my K75
« Reply #1 on: April 18, 2019, 01:43:52 AM »
hi
well i will start with the obvious.
for us to comment on the state of your splines you really need to take a pic end on looking straight down the shaft
there looks to be plenty of meat left on your brake shoe,  but you could get all technical and look up a book and measure for minimum thickness.
and ..... well what do you reckon about the tears in your rubber boots?
they can't do their job with holes and rips in them
  • christchurch, new zealand , where else would u want to live, really
  • 1991 K75RT naked 67,000kms

Offline rbm

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Re: Need experianced eyes on a few pictures by my K75
« Reply #2 on: April 18, 2019, 05:29:38 AM »
Looking at a photo of the outside of your injectors will tell nothing.  They could be ratty looking and still function perrfectly, or they could e pristine yet clogged.  Get them cleaned and tested at a speciality shop.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline The Mighty Gryphon

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Re: Need experianced eyes on a few pictures by my K75
« Reply #3 on: April 18, 2019, 07:54:58 AM »
I like to look at the top of the splines.  The wider the top is, the less wear there is on the spline.  It's an easy photo to take, wipe off the lube, and get a light reflection off the top.  One spline is all you need to judge the wear.  The inner splines are a bit trickier, but the same idea.  I take photos now every time I lube them.

Note the nice wide flat surface on the top of both the inner and outer splines here.  The inner show a little wear as indicated by the slight step in the side of the spline.  At 42,000 miles, there is a ton of life left in these splines.

  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline JoHo

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Re: Need experianced eyes on a few pictures by my K75
« Reply #4 on: April 18, 2019, 08:32:13 AM »
Hey guys. Thank you so much for the response, i Will go and take better pics of the splines ASAP.

What about where the brake pads were? And the pads themselves. How does that look? I have been searching the web but i cant seem to find any answers..
  • Denmark
  • BMW K75 C 1987

Offline Laitch

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Re: Need experianced eyes on a few pictures by my K75
« Reply #5 on: April 18, 2019, 09:17:19 AM »
What about where the brake pads were? And the pads themselves.
Those aren't brake pads; they are brake shoes. Pads are found on disc brake calipers, like your moto's front brakes. Shoes are found on drum brakes like your moto's rear brake.

While wearing a particle mask, clean the mounting plate, the drum surface and the shoes then de-glaze the shoes' surfaces by a rubbing them with emery cloth or 120 grit sandpaper just enough to uniformly roughen the surface. The shoes' friction surfaces must be greater than 1.5mm thickness; yours seem thick enough. Be certain the springs and the damper are installed in the correct positions when reassembling.

Which manual are you using?
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline JoHo

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Re: Need experianced eyes on a few pictures by my K75
« Reply #6 on: April 19, 2019, 08:59:48 AM »
As requested
  • Denmark
  • BMW K75 C 1987

Offline Laitch

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Re: Need experianced eyes on a few pictures by my K75
« Reply #7 on: April 19, 2019, 10:46:12 AM »
As requested
They are worn but have plenty of miles left on them if then are lubed regularly with the correct paste type. Of more immediate concern that has been indicated previously is replacing the boot and cap that are torn. The cap indicated by the arrow in the attached photo covers the gear position indicator switch. The switch needs gentle and careful cleaning: the cap needs to be repaired or replaced so road grime and moisture won't ruin the switch.

  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline rbm

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Re: Need experianced eyes on a few pictures by my K75
« Reply #8 on: April 19, 2019, 12:19:16 PM »
Another observation. The clutch cup is broken and needs to be replaced.  It's allowing transmission fluid to leak through the clutch pushrod, which you can see has smeared all over the outside of the transmission.  When you do replace it, make sure that the clutch actuating arm is not hanging free as shown in your photo.  There is a strong spring inside of that cup which will tear the rubber of the cup if not restrained by the clutch actuating arm.  Whenever you remove the clutch cable, wire up the clutch actuating arm so that it is always pressing against the pushrod by fastening the arm to the transmission using a piece of wire or tiewrap.  That will prevent damage of that cup.

  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline The Mighty Gryphon

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Re: Need experianced eyes on a few pictures by my K75
« Reply #9 on: April 19, 2019, 01:02:36 PM »
As requested

Yikes!   Those shaft splines are pretty bad, but very usable.  I would start looking at shafts to see if I could pick up a better one for a good price..
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline JoHo

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Re: Need experianced eyes on a few pictures by my K75
« Reply #10 on: April 20, 2019, 04:48:41 PM »
Laitch
- thank you for pointing that out with the clutch. But it’s the picture that was weird. The switch seems fine and there is no tear there.

The clutch rubber boot needs to be switched though..: anyone know the parts number for that?

I have some new photos for you guys to help look at...
I noticed when removing the exhaust manifold that one of my cylinders seems to be sweating a tad more than the others .. I’m kinda concerned - should i be?
  • Denmark
  • BMW K75 C 1987

Offline Laitch

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Re: Need experianced eyes on a few pictures by my K75
« Reply #11 on: April 21, 2019, 02:07:24 AM »
- thank you for pointing that out with the clutch. But it’s the picture that was weird. ..
I noticed when removing the exhaust manifold that one of my cylinders seems to be sweating a tad more than the others .. I’m kinda concerned - should i be?
What I was indicating wasn't a clutch part. It was the cover for the gear position indicator switch. If its cover is not damaged, seal its edges and surface with silicone sealer or equivalent product to inhibit damage from water, grit and heat.

I don't notice "sweat" in a cylinder, but I do notice what appears to be a spark plug that seams to be overheating. Its color should not be white if it is firing. Overheating can occur from air leaks causing a fuel mixture that is too lean. All the throttle body manifolds and the crankcase breather should be checked for leakage and cracking; the vacuum port caps on the throttle bodies should be checked.



Put checking the valve clearances on your task list too, if it isn't there already.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline JoHo

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Re: Need experianced eyes on a few pictures by my K75
« Reply #12 on: April 21, 2019, 03:04:10 AM »
Laitch
Oh! Right. I apologize. English is not my first language and all of this is pretty new to me with technical terms. I will clean it and seal it, the gear position cover that is.


What I meant about “cylinder” was the hole in the bottom of my block where the exhaust manifold goes. One of them has a lot more black stuff inside and a more brown’ish color like in the picture.

Valve clearences, check. Thank you again for all your help. I feel a lot better doing this project with this awesome forum for guideance!
  • Denmark
  • BMW K75 C 1987

Offline Laitch

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Re: Need experianced eyes on a few pictures by my K75
« Reply #13 on: April 21, 2019, 05:07:34 AM »
Laitch
Oh! Right. I apologize. English is not my first language . . .
Apology is unnecessary. Clarification is the goal so that understanding is shared.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline rbm

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Re: Need experianced eyes on a few pictures by my K75
« Reply #14 on: April 21, 2019, 09:42:13 AM »
Replace the copper exhaust gaskets when its time to finally put on the exhaust header.  New gaskets will seal better and prevent blow-by and that carbonisation you are experiencing.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline volador

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Re: Need experianced eyes on a few pictures by my K75
« Reply #15 on: April 22, 2019, 05:00:16 PM »
Replace header nuts with Stainless Steel or Monel nuts. Use copper anti-seize when fastening together
  • NYC NY
  • 1991 K100RS 1993 K75S ABS
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Offline Past-my-Prime

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  • All of us are better when we're loved.
Re: Need experianced eyes on a few pictures by my K75
« Reply #16 on: July 05, 2019, 10:20:48 PM »
I don't think this is a hijack. Hopefully HoJo's got it all good and running again. Question: volador mentions copper anti-seize. However, is there an issue using this in an aluminum housing? I've seen copper anti-seize mentioned a few times on a few threads. But I'm worried.
  • North Shore of Lake Superior (in my garage)
  • BRICK: 1989 K75 RT - Rocinante; NON-BRICK: 2007 F650 GS Dakar - Betty Blue

Offline rbm

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Re: Need experianced eyes on a few pictures by my K75
« Reply #17 on: July 05, 2019, 10:29:33 PM »
Copper anti-seize is fine in this application (Exhaust header nuts threading onto header studs).  The anti-seize prevents galvanic corrosion.  It's use is almost mandatory where stainless steel bolts or studs will be threaded into aluminum.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

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