K75S fuel injector hose routing?

[crgrbrts]

Having been plagued by a fuel leak on my K75S recently -- corrected by a substantial, almost-to-the-limit tightening of the hose clamps -- I decided to replace fuel injector hoses.

Both hoses to the fuel rail were showing signs of age (well, they are 17 years old). Replacing the front one was easy. I just loosened the left hand fairing and was able to access the top fitting on the fuel tank.

The rear feed hose, however -- from which my leaks have actually come -- is a mystery to me. Where is the top fitting and how do I get to it most readily? Parts diagrams have been no help. I don't wish to disassemble the bike more than necessary or remove the tank when I should be taking off the airbox or vice-versa.

Many thanks.

[cayuse60]

The second line coming down from the front left of the tank is feed from the pump to the rail (high pressure fuel injector line). The first front line going to the tank is low pressure return to the tank from the fuel pressure regulator. The rear line is high pressure return from the fuel rail to the fuel pressure regulator.
With the airbox out it is an easy change. MAKE SURE the high pressure lines are pressure rated for fuel injection (100 psi).

If you are using 5/16th (8mm) fuel injector clamps you can not over tighten them. They are made to fit the line. Replace the old clamps.

----tim

[crgrbrts]

Many thanks for the info, Tim. I've got the properly rated BMW logo-decorated injector hose and shiny new clamps, so I'm good to go. There's nothing like raw fuel dripping off your left boot to cause you to rethink your riding plans.

[cayuse60]

Many thanks for the info, Tim. I've got the properly rated BMW logo-decorated injector hose and shiny new clamps, so I'm good to go. There's nothing like raw fuel dripping off your left boot to cause you to rethink your riding plans.


....or the soon to follow fire with the exhaust right below your left foot:uhoh

safe riding---tim

[Burnszilla]

Those clamps are called oetiker clamps and you need special oetiker crimp tool to clamp them. There probably is another way to crimp them and someone will chime in..

[BuddingGeezer]

There are special fuel injection clamps, that tighten with a screw driver. Any auto parts store has them. I just bought some this week at Advance Auto Parts.

Ralph Sims

[breyfogle]

Oetiker style clamps are nice on the pressure regulator connections because the location makes any clamp impossible to re-tighten without removing alot of stuff. Fuel injection rated screw clamps are fine on the fuel rail connections and the fuel tank connections.

[crgrbrts]

Hmmm. I don't think I'll be using an Oetiker clamp on the bottom of my fuel regulator unless I can find a source that will sell me less than 100. Then there's the clamping tool, which I'd be using about once a decade.


The hose clamp now installed appears to be an ordinary worm-drive type. What about replacing that with one of the BMW clamps that's I've got on the opposite of the fuel injector hose?

[BuddingGeezer]

All my clamps on the fuel system are worm drive. 7000 miles no problem. Fuel injection clamps are better, but I had a handfull of wormdrive when I replace the fuel lines.

Ralph Sims

[cayuse60]

Hmmm. I don't think I'll be using an Oetiker clamp on the bottom of my fuel regulator unless I can find a source that will sell me less than 100. Then there's the clamping tool, which I'd be using about once a decade.


The hose clamp now installed appears to be an ordinary worm-drive type. What about replacing that with one of the BMW clamps that's I've got on the opposite of the fuel injector hose?

5/16th fuel injection clamps or the BMW clamps you have are the replacement for the original clamp...again they are made for the diameter of the fuel line used and can be tightened to their limit. you can see the lines and connections to and from the fuel pressure regulator from the back left side of the engine for a leak check. I just replaced all the external fuel lines on my 1991 K75 and every thing is tight and "happy". :)

[crgrbrts]

"I just replaced all the external fuel lines on my 1991 K75 and every thing is tight and "happy".

Thanks, Tim -- oh, did you remove both the tank and airbox to get to the fuel pressure regulator?

[cayuse60]

"I just replaced all the external fuel lines on my 1991 K75 and every thing is tight and "happy".

Thanks, Tim -- oh, did you remove both the tank and airbox to get to the fuel pressure regulator?

very late reply.....yes

[Kayseventyfive]

I chased a leak and found some of my oetiker clamps allowed the hoses to be pulled off easily. My guess is that this was due to the hoses shrinking. I replaced the hoses with fuel injection line and the screw-type fuel injection clamps. They at least, allow me to fix a leak by tightening a screw, which is easier to do out on the road than tighten an oetiker clamp.