Author Topic: 87 K75C, Bone Stock and DONE.  (Read 52228 times)

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #50 on: October 09, 2016, 07:59:52 PM »
The unfinished aluminum cleans up nicely doesn't it!
Your post on the clutch rod leakage had me looking while I repaired my rear brake switch.
I've got a little leak also...

Don in Nipomo
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline trek97

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Re: New to me 87 K75C/T
« Reply #51 on: October 09, 2016, 09:18:47 PM »
The unfinished aluminum cleans up nicely doesn't it!
Your post on the clutch rod leakage had me looking while I repaired my rear brake switch.
I've got a little leak also...

Don in Nipomo

It takes a bunch of elbow grease, but, yes it sure does.
and Bummer bout the leak.  Adjusting the clutch to spec helped a bunch.  After sitting all day.  the boot does has a dribble on it.  But not a drop on the floor yet.  Before adj clutch there was a puddle collecting under her over the past week.
  • Illinois
  • 87 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #52 on: October 10, 2016, 12:47:33 AM »
No puddle here just a single drop while I was scrubbing away at the peg/brake pedal assembly.
Took it all off to service the micro switch. I dunno, not much you can do there. Might get a different one...
I don't get a consistent triple 0 on the 2k setting with my meter. The connector ends jumps out just fine to initiate the rear brake light.

The aluminum castings brush up pretty good. Coat it with paste wax.
I scrubbed the hell out of my bike when I got it, I like a clean slate to start with.
Simple green, wire brush and a small focused power washer.
That drip out the end of the clutch rod on to the floor was the first. This unit is fairly tight.


Don in Nipomo
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline trek97

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Re: New to me 87 K75C/T
« Reply #53 on: October 10, 2016, 07:02:26 AM »
Posted by Inge K in my other thread...


Is the oil level in the gearbox correct .....?....it should be much lower than the shafts.

Now that shes back on the ground.  I was curious to see just how much oil was in the gear box.  Set to MAX level.



Oh bout 30mm too much!  Fingers crossed, the internal seals did their job and it didnt get into the clutch.  Argh!



I'll get this draining now.  And refill properly when I get home from work.
  • Illinois
  • 87 K75C

Offline trek97

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Re: New to me 87 K75C/T
« Reply #54 on: October 16, 2016, 04:59:47 AM »
Looking like draining and refilling gearbox to the proper level, did the trick. 

Over the past week the leak slowed and now have none!

Cleaned tank out.  yuck.







Pulled the pump out and the screen looks to be in decent shape.





tank topped off w a new gasket.



anyone know what the two smaller crush washers w the oil kit are for?



Found old breather tube cracked.  I replaced it w new.





found the radiator cap was missing the large gasket.  Luckily the kit included both gaskets.











  • Illinois
  • 87 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #55 on: October 16, 2016, 08:19:58 AM »
Looking good!

 How were things under the airbox?
 Was there much goo on the backsides of those throttle bodies?

You know, if you keep this up (cleaning and/or replacing everything) sooner or later you'll have to start it up and ride.


Don in Nipomo
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline trek97

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Re: New to me 87 K75C/T
« Reply #56 on: October 16, 2016, 09:23:39 AM »
Looking good!

 How were things under the airbox?
 Was there much goo on the backsides of those throttle bodies?

You know, if you keep this up (cleaning and/or replacing everything) sooner or later you'll have to start it up and ride.

Don in Nipomo


Thanks bud,

Got the title, plates and insurance yesterday so I am officially ready to roll.

However, found my front tire is slowly leaking air around the valve stem.  Aargh!  But getting her back together right now.  So, a tire pressure check and a short cruise around the block this afternoon.  Once it stops sprinkling rain.

Also, got the broke front signal replaced.  All the lights work off the key but the brake light threw me for a short loop.  But after going through wiring schematic found its powered from the kill sw.  Which I had in the kill position.  Works as intended, w warning light on the dash, light monitor unit and hit both brake controls.   :2thumbup:     

I didnt pull the airbox all the way out.  They got it swedged in there pretty darn tight. 
I pulled the snorkel off, and was able to pull the top just enough to slip the old out filter and new into place.

I can see its kinda nasty under the box though.  I jammed a tooth brush around under there as best I could.  Mostly from front side.  I will re-visit that once the snow starts flying.  And I strip her down for paint work.

Made a decent deal on a clean old stock BMW seat, to replace the giant seat currently installed.  Its a solo seat similar to yours.  Only without the nifty little fold down back rest yours has. 

and Yes,  its pretty brown under and behind the throttle bodies.  Is that a sign of leaking fuel?
  • Illinois
  • 87 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #57 on: October 16, 2016, 09:37:39 AM »
I put 712s on mine also. No leaks from the old stems.
The breather hose sucks and blows so some of that grunge is a result of that.
The throttle body rubbers will also contribute to the mess along with general road spray and a little coolant leaking.
The lower half of the filter airbox plenum was a mess on mine, glad I tidied it up.

My K75 was mostly in boxes so it was easy to go the full route on cleaning.
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline The Mighty Gryphon

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Re: New to me 87 K75C/T
« Reply #58 on: October 16, 2016, 09:43:18 AM »
I had the same slow leak around the valve stem on my RS.  I painted some soapy water around the stem and with about 25 PSI in the tire gently rocked the stem back and forth to work some of the soapy water into the joint.  Gently spun the stem back and forth about 45 degrees and the leak stopped.

Took about 5 minutes all together.  Was very glad I didn't have to remove the tire or even take the wheel off the bike.
  • 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 trek97

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Re: New to me 87 K75C/T
« Reply #59 on: October 16, 2016, 01:22:54 PM »
I had the same slow leak around the valve stem on my RS.  I painted some soapy water around the stem and with about 25 PSI in the tire gently rocked the stem back and forth to work some of the soapy water into the joint.  Gently spun the stem back and forth about 45 degrees and the leak stopped.

Took about 5 minutes all together.  Was very glad I didn't have to remove the tire or even take the wheel off the bike.

OK going to try it.
  • Illinois
  • 87 K75C

Offline trek97

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Re: New to me 87 K75C/T
« Reply #60 on: October 16, 2016, 02:44:10 PM »
I had the same slow leak around the valve stem on my RS.  I painted some soapy water around the stem and with about 25 PSI in the tire gently rocked the stem back and forth to work some of the soapy water into the joint.  Gently spun the stem back and forth about 45 degrees and the leak stopped.

Took about 5 minutes all together.  Was very glad I didn't have to remove the tire or even take the wheel off the bike.

 little soap a couple twists and I think it may have done the trick.  WOW thanks dude!  Ill recheck it in a couple days. 

Finally stopped raining so gonna take her out for a shakedown cruise in the next hour or two!!!
  • Illinois
  • 87 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #61 on: October 16, 2016, 03:25:42 PM »
"Finally stopped raining so gonna take her out for a shakedown cruise in the next hour or two!!!"

Do it and begin to get it tuned in. Run it hard and then dump the oil. Wouldn't hurt.

 Between storms out here on the Central Coast also.
 Been months of no measurable precipitation. Got about and inch, maybe more.
Just back from a little romp on mine.

The foot switch for the brake light is still giving me trouble.
Operation is inconsistent at best, guess that little arm has been bent way too many ways!
Ebay replacements on watchlist. Cheap enough.
Front hand switch is fine, I just want to put the bulb monitoring unit and my mind at ease.
Annoying having to pull that cover and set up my meter again and again.

Don in Nipomo





  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline The Mighty Gryphon

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Re: New to me 87 K75C/T
« Reply #62 on: October 16, 2016, 04:03:39 PM »
little soap a couple twists and I think it may have done the trick.  WOW thanks dude!  Ill recheck it in a couple days. 

Finally stopped raining so gonna take her out for a shakedown cruise in the next hour or two!!!

 :2thumbup:
  • 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 trek97

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Re: New to me 87 K75C/T
« Reply #63 on: October 16, 2016, 06:45:22 PM »
Got her all bolted back up today and took her for a real ride. 

She fumigated the garage on startup but completely cleared up as soon as I hit the pavement. 

Once home...Set idle speed down to 950ish.  According to the gauge.

Everything functions exactly as the boys over at BMW intended.  She is a smoooth, rock solid machine. 
I am delighted.

Not gonna do too much real work over the next month or so, its Whitetail Season.  Just gonna keep cleaning (need to get the engine shining to match rear end, lol) and ride her when weather permits.

After hunting season I will strip her down and prep her for paint and finish the clean up and go through the throttle bodies, pull oil pan, etc.

I will keep posting pics and questions as I get things done.  Thanks for all the tips guys.
 

  • Illinois
  • 87 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #64 on: October 16, 2016, 07:23:30 PM »
 :2thumbup:
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #65 on: October 16, 2016, 07:33:58 PM »
If you take a small mill bastard to the face of those fins on the block that surround the oil sightglass it will really "pop"!

Don in Nipomo
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline Martin

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Re: New to me 87 K75C/T
« Reply #66 on: October 16, 2016, 08:02:42 PM »
 :2thumbup: Looks like your off to a good start. Ride it and enjoy it. You have just got to love the Bricks.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline The Mighty Gryphon

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Re: New to me 87 K75C/T
« Reply #67 on: October 16, 2016, 08:20:17 PM »
Nice looking bike!  The more you ride it the better it will run after being neglected for a while.  Been looking at my RT sitting in the garage waiting for the fairing to go back on.  These machines look great in the raw.  You have a great one there.
  • 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 trek97

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Re: New to me 87 K75C/T
« Reply #68 on: October 16, 2016, 09:39:17 PM »
Thanks guys!  I now see why guys get so hooked on BMW.   :riding:

I think Im past my Honda phase.



  • Illinois
  • 87 K75C

Offline trek97

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Re: New to me 87 K75C/T
« Reply #69 on: October 16, 2016, 10:41:47 PM »
Hey guys, doing some homework.  I came across some specs and they say this machine has 11 to 1 compression.

Should I be burning nothing less than 91 octane fuel?
  • Illinois
  • 87 K75C

Offline D.Bachtel

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Re: New to me 87 K75C/T
« Reply #70 on: October 17, 2016, 12:10:57 PM »
I use super or premium fuel in my K75. Chevron Techron or Union 76.

Do a compression test on your K75, you should get some pretty high psi readings.
Not quite diesel range but up there...
I was pleasantly surprised with 175 across the board, could be my old tester but I was impressed.

Don in Nipomo
  • Nipomo
  • BSA, Zundapp, Husqvarna, Greeves, Triumph...and a 1987 K75C

Offline herseyb

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Re: New to me 87 K75C/T
« Reply #71 on: October 17, 2016, 12:21:12 PM »
Up here in Wisco, I use premium no alcohol whenever available, which is usually.

Otherwise I use regular ole cheapy gas if I'm forced to burn alcohol - never had problems with it.
  • Madison, Wi
  • '90 K75

Offline trek97

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Re: New to me 87 K75C/T
« Reply #72 on: October 17, 2016, 07:14:45 PM »
I burn 91 octane pure gas in the Hondas, simply due to the carbs.  Looks like Im starting the hunt for something even better.

For anyone hunting pure gas = no ethonal. 

Heres the link to the list. http://pure-gas.org  Click on your state at the bottom.

You can add a station to the list if you already got one and its not on there.  Or delete if a station stops selling it.
  • Illinois
  • 87 K75C

Offline The Mighty Gryphon

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Re: New to me 87 K75C/T
« Reply #73 on: October 17, 2016, 07:58:56 PM »
I have two gas stations nearby that sell pure 91 octane gasoline and for two years that is pretty much all I ran in my three bricks.  This year I tried using the 10% ethanol 87 octane, and found that there was no discernible difference in performance and only a 2 or 3 mpg difference in fuel efficiency.  As a result, I now pretty much run that stuff full time and pocket the $2+ difference in cost at each fillup which adds up as I ride my bikes over 500 miles per week. 

However, at the end of the season I will be switching over to no ethanol gas mixed with a dose of Techron and Stabil for the last week or two of operation and this is what they will be put away for the winter with.  I'm doing this to avoid the documented problems that are caused by old ethanol gas.
  • 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 trek97

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Re: New to me 87 K75C/T
« Reply #74 on: October 17, 2016, 09:54:44 PM »
Good info, thanks bud.
  • Illinois
  • 87 K75C

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