Author Topic: BMW 92' K75S - A "Flying Brick"  (Read 25431 times)

Offline jonnyTHUNDERmaker

  • Posts: 609
BMW 92' K75S - A "Flying Brick"
« on: Jun 01, 2012, 17:44:49 »
This is my first "modern" bike and first BMW. I am learning and discovering a lot. Its a 92' BMW K75s with about 30k on the clock. These old "Flying Bricks" are amazingly reliable and are known to go 400K no big deal. Apparently there is some guy who has pushed his over 1,000,000  :o

Mine was in pretty rough condition. It ran, but very poorly. Looked like it had been layed over at low speeds or just in the garage multiple times on each side.

Bikes History: From what I can tell it started life as a much loved and cared for bike. The first owners must have used it what it is good for, sport touring. Decent service records at the beginning of its life and some of the first owners spent time and money adding things like:

Upgraded to the K75 "C" bars: These are a bit higher, less sportier, and better for long distance traveling

Aftermarket windshield: Parabellum Air Balance windshield system - Pretty goofy looking, but good for touring and does a good job at stopping the wind

Heated grips: Not sure if these work or not, I havent really messed with them

Hazard flasher system

Upgraded tail and running lights

Motocom, power port, and some other things.

The bad news is the last owner whom I purchased it from really did the bike wrong. It really makes me mad when people buy nice things, in this case a fairly expensive bike, and don't take care of it.  >:( Poor to no service records too

From what I can see, and based on the damage and condition of the bike, the last guy bought the bike or had it given to him. He didn't know crap about taking care of a motorcycle, much less a BMW. He layed it over multiple times, got scared or frustrated and just let it sit; with gas is it of course.  >:(

Thats where I came in. I found it on CList for an okay price and negotiated a bit and ended up with a decent deal ;)

So far all my work has been primarily to get this bike back to its happy old self with all the maintenance needs and take care of it like it deserves to be treated.

Here is how it looked when I picked it up :'(

Offline jonnyTHUNDERmaker

  • Posts: 609
Re: 92' BMW K75S
« Reply #1 on: Jun 01, 2012, 17:59:46 »
As it is today. I LOVE THIS BIKE. It is so smooth and powerful. Feels pretty nimble for a 500lb bike too.

I have gone through and done nearly every tune up/maintenance need on the bike. Trying to keep a solid record of everything too. I just have a couple more to do.

So far:

Add Brake Fluid              - Valvoline Syn Dot 3&4   
Replace Oil + Filter        - Bosch 3330, Valvo 20W50   
Replace Fuel Filter        - Napa Gold Fuel Filter   
Replace Fuses                - 7.5A +15A   
Replace Final Drive Oil    - Mobil 1 Syn 75w/90   
Repair Headlight Switch - WD40, sandpaper, solder - Clean and resolder contacts
ReplaceTransmission Oil - Valvoline Syn 75w/90   
Replace Air Filter        - BMW filter   

Still need to:
Perform final drive spline lube      - Use Guarddog Moly GD-525
Flush and refill coolant system
Flush and refill brake system
Install new tires                           - Have Bridgstone Spitfires in the mail
Check brake pads
Replace Crank case breather hose - mine is cracked and causing the bike to run a little lean
Replace spark plugs                      - came in the mail yesterday
Add Fork boots                             - came in the mail yesterday

Cosmetically I have mainly been cleaning things up and done a little bit of painting. The sidebags were trashed from the bike being dropped on them multiple times. I repaired them with some epoxy and sanded and painted them with some Duplicolor Truck Bed liner.

Also painted the coil cover, alternator cover, rear fender and inner fender, and the lower windshield (the black section)

Slowly, but surely it is cleaning up.

I plan to get it back to tiptop running condition and take it for some nice long rides. Austin to Denver this fall for a backpacking/hunting trip is on the books already ;D

Here is what it looks like now

Any BMW gurus out there feel free to offer pointers and criticism. Like I said this is my first BMW and am learning a bunch

Offline doorpz

  • Posts: 31
Re: BMW 92' K75S - A "Flying Brick"
« Reply #2 on: Jun 02, 2012, 04:32:28 »
Looks great man, I like the belly pans that come on the S models. I'm working on mistreated k75 project right now too, '86 k75c. The gas had been sitting in the tank so long that all the internal steel components rusted out and the aluminum tank actually corroded holes all the way through. I sent the fuel injectors out to be rebuilt and and the guy told me they were too messed up to be rebuilt. I'm now looking for a new tank or somebody who can TIG the patch panels into the tank. I'm also new to the BMW's but it's a nice looking bike and I'm excited to get it on the road, should be a good highway cruiser. I'll be following your build and stealing all your ideas, haha. Keep up the good work.
« Last Edit: Jun 02, 2012, 04:39:23 by doorpz »

Offline jonnyTHUNDERmaker

  • Posts: 609
Re: BMW 92' K75S - A "Flying Brick"
« Reply #3 on: Jun 02, 2012, 13:59:01 »
Cool man,
Yeah I love the look of these old blocky motors and the belly pan. That's a bummer about the tank and injectors. My tank actually has a couple really tiny pinhole leaks in it. I just have to clean it off really well and should be able to patch them no problem.

Keep at it. They are a blast to ride. There is a ton of info as they have a decent cult following. Check for parts if you have already. He's a nice guy and may be able to point you in the right direction. Keep me updated. Do you have a build blog on here?

These bikes LOVE the highway. They are so smooth

Offline jonnyTHUNDERmaker

  • Posts: 609
Re: BMW 92' K75S - A "Flying Brick"
« Reply #4 on: Jun 02, 2012, 14:22:44 »
Well last  night when I got home from work my rear tire had arrived :) The front came in a couple days ago.

I immediately went to work. Wrestled with the old tires till I was completely beat. 3 hrs later I had two new Bridgstone Spitfires on the bike. Changing tires is a huge pain without ALL the right tools.

The new tires feel great. I also lowered the front of the bike about a quarter of an inch. Just slid the fork tubes up through the triple tree. The combination of the new tires and the slightly lowered forks makes the bike feel so much more nimble.

My spark plugs and fork boots came in as well I just have to find time to install them.

Offline jonnyTHUNDERmaker

  • Posts: 609
Re: BMW 92' K75S - A "Flying Brick"
« Reply #5 on: Jun 02, 2012, 14:29:02 »
Ughhhh.  >:(

Last night when I was cruising home somehow one of my saddlebags popped off my bike but was still connected with the latch so it was just resting on the muffler. I didn't hear or feel it so it sat on my muffler for a good 10 minutes.

When I got home I found it and now there's a nice fat six-inch hole melted through the bottom of my saddlebag. Luckily I was able to get all the melted plastic off of my muffler and I should hopefully be able to repair the saddlebag with some fiberglass. It will be ugly but it's on the bottom of the saddlebag. What a pain

Offline doorpz

  • Posts: 31
Re: BMW 92' K75S - A "Flying Brick"
« Reply #6 on: Jun 02, 2012, 23:51:27 »
Sucks to hear about the saddlebag. I don't have the key for the saddlebags on mine so I can't even get them off if I wanted to. I might have to drill out the lock or see if there is a key code on them so I can order new ones. I like the look of these bikes without the bags but they are just so practical I'll probably leave them on. I haven't heard of the beemerboneyard, thanks for the heads up I'll check it out. I'll start a build thread on it once I really get into it. So far I've only been messing with the tank.
I have a few pictures on photobucket but they're mostly of the tank.

Are you planning on adjusting the valves at all? I thought about doing it now while I have the bike torn down already. I looked through the procedure in the manual and it doesn't seem like it would be very hard. If I recall correctly these motors are shim over bucket.

Offline jonnyTHUNDERmaker

  • Posts: 609
Re: BMW 92' K75S - A "Flying Brick"
« Reply #7 on: Jun 03, 2012, 01:51:51 »
Yeah the saddlebags are super handy. I had them off for a while and now that they are on I use them for everything.

I thought about the valve adjustment. Haven't really looked into it to much. I'll have to add that to my list of things to do

Let me know if you have any questions. I am definitely new, but have been reading way to much about these bikes  ;)

Ps. Once you get your tank all fixed up you will want to insulate the bottom of it as best you can. Apparently the tank can get pretty hot after longer rides

Offline jonnyTHUNDERmaker

  • Posts: 609
Re: BMW 92' K75S - A "Flying Brick"
« Reply #8 on: Jun 03, 2012, 15:52:00 »
Here are some inspirational pics of what I am leaning towards for this bikes future. I like certain elements of all these. I think I am leaning towards a sort of adventure touring/street tracker mix, similar to the first picture.

Renthal bars, fork boots, Acewell or Trailtech Dash, Round headlight with Catz driving lights, small windscreen, bar end or much smaller mirrors, etc. We shall see when the time comes. I want to keep the touring abilities of the bike, but make it a little more aggressive looking


That K1000 is a beast (2nd and 3rd pic)

Offline doorpz

  • Posts: 31
Re: BMW 92' K75S - A "Flying Brick"
« Reply #9 on: Jun 04, 2012, 02:09:35 »
I like the last one, very mad maxish but it seems like it lost most of the touring aspect. The first one and the gloss black one seem to be nice spirited tourers. I like the high front fender on the first one as well, combine that with the tires it has a nice dual sport look going.
« Last Edit: Jun 04, 2012, 02:11:18 by doorpz »