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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: exscouse on May 20, 2012, 09:33:12 AM

Title: Can you help me get an '87 K75S back on the road?
Post by: exscouse on May 20, 2012, 09:33:12 AM
Hi Guys, I've been lurking for a while and the excellent posts have encouraged me to start this project.

The bike has been sitting at the back of the garage for 15 years (please don't ask why).
The master cylinder leaked over the fairing at some point, so I'm going to need some paint work eventually, but I'm just trying to get it running for now.

Here's where I am:
Ordered new battery, oil filter, fuel pump, fuel sender, inside tank hoses.
Cleaned tank with POR15 cleaner, cleaner air filter, cleaned injectors, new brake fluid (followed frankenduck's posted advice and tried a good clean before replacing the master cylinder - seemed to work).

My present dilemma is should I replace the outside tank fuel lines?
They look good but they are 25 years old.
If I do replace them, do I need to use the "single use" hose clamps on the lines connecting to the fuel pressure regulator, or can I just use regular screw clamps?
Do I need to order the specific BMW hoses, or can I just use generic?

Apart from replacing all the fluids and tires, can anyone suggest what else might need attention on a bike that has been sitting for that long?

Thanks for your help.
Title: Re: Can you help me get an '87 K75S back on the road?
Post by: sh00ter on May 20, 2012, 09:43:46 AM
My present dilemma is should I replace the outside tank fuel lines?

* Personally I would, they are no doubt cracked on the ends, and if you're doing it - why not?

They look good but they are 25 years old.
If I do replace them, do I need to use the "single use" hose clamps on the lines connecting to the fuel pressure regulator, or can I just use regular screw clamps?

* You can use a hose clamp designated for fuel injection lines (has external screw, not one that uses the clamp as it's screw).  These are multi-use, not the one-time only clamps.  Worked fine for me.  NAPA had them in stock.

Do I need to order the specific BMW hoses, or can I just use generic?

* I used BMW bulk fuel line rated for high pressure and "submersion" applications.  You can use generic, just make sure it is rated for high pressure (fuel injection) and submersion if it's going in the tank.

There are some good posts up about replacing the fuel lines in the lieberry
Title: Re: Can you help me get an '87 K75S back on the road?
Post by: frankenduck on May 20, 2012, 12:46:57 PM
not one that uses the clamp as it's screw

a.k.a. worm drive hose clamp


You'll probably want to replace the crank case breather hose too (11151460480 - #10)

(http://www.realoem.com/bmw/diagrams/e/d/1.png)
Title: Re: Can you help me get an '87 K75S back on the road?
Post by: frankenduck on May 20, 2012, 12:49:08 PM
Fuel lines: http://www.motobrick.com/index.php/topic,1042.0.html (http://www.motobrick.com/index.php/topic,1042.0.html)

Post #4 has some info applicable to K75s.
Title: Re: Can you help me get an '87 K75S back on the road?
Post by: exscouse on May 20, 2012, 01:23:20 PM
Thank you both,

I didn't see the fuel line replacement thread, it answers my questions.
I'll get some generic 5/16 FI fuel line and use the hose clamps from the inside of the tank.
Attached is what the fuel pump and sender looked like.

I'll get the breather hose.

I was wondering if I should lube the splines, and if there were any seals or other such that would likely have dried out and need replacing.

Thanks again.
Title: Re: Can you help me get an '87 K75S back on the road?
Post by: frankenduck on May 20, 2012, 02:09:38 PM
Can't hurt to lube the splines and on a bike that's sat for so long I'd also replace the clutch nut O-ring while I had the tranny off since it has probably dried and cracked and will soon be leaking. 

See the Lieberry post on K bike clutches for more info.