New Owner 1988 K75 - Have Some Questions

[Texas K75]

I purchased 1988 K75 over the weekend.  I have a 1979 R65 but this is my first water cooled BMW.  I've run the VIN through the decoder and it looks like I purchased a K75C.  The bike does run.  It's very cold natured and backfires quite a bit on deceleration.  Very slow t respond to throttle from idle.  Difficulty idling when cold.

It seems to handles pretty well.  There are a number of cosmetic issues and some of the plastic pieces are missing.

There appears to be a valve cover leak but nothing else leaking that I can see.

I do not know much about the history.  I bought it off of Craigslist for $1,000.00.  The odometer does not work but reads 45K miles.  Speedometer work though it appears to read slower than the actual speed.

I am going to assume that fluids have not been changed since the Clinton administration and change them all.

Questions:
1 - What are the differences in the various K75 models?  K75 vs. K75C vs. K75T vs. K75S vs. K75RT?

2 - Anything I should pay particular attention to? 

Any help would be appreciated.

[frankenduck]

Check the crank case breather hose for wear:




First thing I'd do: Getting Fuel Injectors Reconditioned


Also: My K runs like crap at idle but does OK at higher RPMS


And: Fix a flaky or inoperative K bike speedometer


Backfire: All K75s backfire under medium to heavy engine braking.  The more you ride it the more you'll subconciously learn not to.  I haven't backfired a K75 in lord knows how many miles - but I could if I wanted to.

Different models: http://www.motobrick.com/index.php/board,26.0.html

Are you sure you want to mention Clinton and fuilds in the same sentence? :nono

[argent brick]

Welcome to motobrick.com, Texas K75,

Fellow Brickheads would love to see what you have for a bike. How about some pictures of your new machine?

Although the "C" is not as sexy or cool looking as the "S" model, you still have great machine that will turn heads. I have a standard model and mine gets looks. What color is your K75 "Cockpit"?

[mjydrafter]

Welcome.

I would read up on splinetology, by L. Duck Hubbard. :neener:

Check out your fuel lines and look around in the tank for disintegrating fuel pump damper.

Other than that about anything you might run into should be here, or if not ask.

[detbmw]

Welcome to the forum!

I'm up the road a bit in Nacogdoches, maybe we can go for a ride someday. I know you are on the other side of Houston from me, but if you are up this way we have an MOA club meet the first Thursday of the month in Jacksonville and a Two-Wheeled-Texans ride-to-eat somewhere in East Texas on the second Thursday of the month.

We are also planning a weekend camp out this spring near Sam Rayburn Reservoir and there is a side-car rally in May near Toledo Bend Reservoir (on the TX side).

[Texas K75]

Thank you for all of the responses.  I hope I can address them all in a single note without too much run on.

Frankenduck - Great links.  Thank you very much.  I will start with these and see what improvements they generate.  Thank you so much for the effort you've put into this site.  It's a treasure trove of information for a newby like me.

Argent - This is only my second post.  Not sure I have figured out how to attach a picture correctly.  If the picture did not make it, I can put it in percpetive this way.  Your bike looks like a swimsuit model, mine looks like a crack ho - but I do hope to change that.  It's missing plastic and someone spray painted the tank and remaining plastic with a can of Rustoleum.  They then scratched the overspray off of the BMW badges making them quite unsightly.  There is a giant piece of tape that runs from one piece of the front fender to the other.  Not sure why but I'll bet it's going to cost me some money to replace the tape.  The photo I am posting does the bike way too much justice.

MJY - Thanks for the tip on the fuel lines.  I will inspect them closely.  I'm not smelling gas now but who know how old the fuel lines are.

DET - Thank you for the warm welcome and the Thursday invites.  Unfortunately work is going to keep me down here during the week but you never know, I may be assigned a project that would have me up your way.  If so, I will let you know.  Same goes if you are down here in Houston.  I went to a BMW club meeting down here about 5 years ago.  At 44, I was the youngest one there and I had the oldest bike (my 79 R65) and the only airhead.  The folks were great.  I should probably look into joing the group now that I have two.

I will post on progress.  I'm sure that I will have many more questions.  I hope to start work on the bike in earnest in the next couple of weeks.

[argent brick]

LOL, Did the last owner of your bike use all his money to buy drugs and then try to run your bike on meth?

There is nothing worse than a older woman who insist on wearing clothes designed to show off the figure(and skin) of a 16 to 20 year model. Picture if you will, a 65+ year old woman wearing a sexy see through top, black leather mini skirt and go go boots.  You might like it from a long distance away, but up close it is disappointing. That would be my bike. I will post a picture when I get a chance.

If your bike is mechanically sound then your set. If not, fix that first and then worry about looks.

"Your bike looks like a swimsuit model, mine looks like a crack ho...."  That's great.

[detbmw]

I found the color evolution of the early K's interesting. Mine is an '88, manufactured in July '87, and it has a silver engine block (you can see the corners of it), then it is black from the valve & crankcase covers back to the final drive. My Y-spoke wheels are also mostly black.

Yours has the black engine covers & intermediate housing, but is silver from the tranny to the final drive. I think the very early ones were all silver.

Does anyone know, were the engine blocks always silver? Or did they start making them black at some point?

[frankenduck]

Early ones were all silver.

Yes, they later made black motors. (Or at least cylinder heads, not sure on the block.)

EDIT: I just looked at some motors on Fleabay and it looks like all of the blocks were bare gray.

What your bike has on it now might not be the way it came from the factory.

[Texas K75]

According the the VIN decoder, mine is also a July 87 build

[detbmw]

According the the VIN decoder, mine is also a July 87 build

Cool, our bikes are from the same batch!

Just not identical twins.

[argent brick]

I found the color evolution of the early K's interesting. Mine is an '88, manufactured in July '87, and it has a silver engine block (you can see the corners of it), then it is black from the valve & crankcase covers back to the final drive. My Y-spoke wheels are also mostly black.

Yours has the black engine covers & intermediate housing, but is silver from the tranny to the final drive. I think the very early ones were all silver.

Does anyone know, were the engine blocks always silver? Or did they start making them black at some point?

My '95 K75 has a silver block w/ black valve & crankcase covers and trans. When did they stop making silver valve covers?

[Westone]

My '88 S model has an all black engine and drive train. My understanding, from what I've read around the internet, is that in MY88 the S model got all black. Looks like maybe the other models got whatever was closest at hand when it was time to bolt on a component.