Hello,
I had to change the fuel lines on my K1100RS, as the old ones showed little cracks on the surface.
After this renewal, I have no fuel coming to the injector rail.
Checked the fuel pump, delivers 2,5 bar and runs when I turn the ignition key on and the kill switch off.
Made the connections as follows:

From the gas tank (fuel pump outlet) to the pressure regulator (central pipe),

From the pressure regulator (side pipe) to the injector rail.
From the injector rail to the gas tank (pipe of the return line).
No vaccuum line on the pressure regulator (not foreseen)



My question is how can I figure out what's the inlet side and the outlet side of the pressure regulator, no arrows or indication on it.
Did I swap the connection of the fuel pump line and the return line on the gas tank?

Thanks for helping me out,
Luk

Are you 100% happy with the routing of the pipes in that photo?

I am more familiar with the K100 and not the K1100 but I had thought the pipe routing would be fairly similar. The one on the left of the infector rail [marked to regulator] is down against the cylinder head which does not strike me as ideal, its very close to the hot head.

On the K100 2 valve that pipe is vertical and goes straight up to a spigot on the gas tank. The right hand pipe on the fuel rail []nearest your foot] goes back to the fuel pressure regulator and from there to the petrol tank. Not sure if its the same on the K1100.

I don't have the Clymer near me just now to check.

Looks a bit arse about to me... but i'm not familiar with the 1100
- Line from the fuel pump looks to be going to the regulator.
- Return line from the rail should go to the regulator but looks like its heading off to the tank.
- Fuel line to the rail is coming from the regulator.
This doesn't look right.
....if you've labelled the photo correctly???

First the FPR must be after the rail (or else you have operating pressure only in
the hose between the tank and FPR).

And the flow goes in the opposite direction to the arrows in the picture of the FPR.

If you swap the hoses at the tank it gonna be correct.

Inge,
I connected the FPR just after the fuel pump.
It's becoming clear to me that the FPR should be after the injector rail.
The FPR is blocking fuel going to the injector rail the way it is connected now.
I'll swap the return line and the fuel pump line on the gas tank.
Luk

Olav,
I'm aware that the line on the left hand side of the Injector rail is making contact with the engine block.
I tried to re-route this line, but couldn't find an alternative.
It seems that it's meant to be connected lile this.

Luk

Kaptain Holister.
The arrows I drew on the picture is how I made the connections, and represent the way the fuel will flow.

Luk

Hey guys,

Thanks a lot for your support. I swapped the fuel pump hose and the return hose at the gas tank, as Inge suggested.
Guess what, the bike started after 5 sec, the time to fill the injector rail with fuel.

Gratitude,
Luk

Luk

That's great is going now, but will you put up a photo of what's there now. I am worried about that fuel line down against the engine.

Don't want anything to happen to you!

Olaf

Olav,
Thank you for being concerned about my safety.
This is how the hoses are connected after correction:


I consider wrapping some insulation cloth (the one some people wrap around exhaust pipes) over that hose.
Just to prevent the rubber to burn. Normally if my cooling system is working correctly, the engine block shouldn't exceed a temperature of 95°C.
What do you suggest? Is there an other way to route this hose?

Luk

That is the correct place for the fuel line you may wish to put some insulation on the hose if heat in the fuel tank is a problem, in Europe I doubt it would be any problem.

We don't get too much heat up here even in our summer. But in mainland Europe we can see 35-40c in summer. I know the fuel hose is good stuff and was just concerned it might not be in the correct position.

Now its a case of go get on the K and enjoy it!

Rick G,

Never had issues with fuel being extremely hot in the tank, in Belgium summer temperatures seldom exceed 35°C.
I draped the bottom of the tank with insulation sheet. Some kind of aluminium foil used on the firewall of cars, that helps a lot preventing the tank from heating up.
Didn't notice that the Injector rail return hose made contact with the engine block until Olav drew my attention to it. For my peace of mind I'll put some insulation tape around it.

Luk

I insulated mine and run a small cooler in front of the radiator but the only drawback with that is the tank stays cool in winter so my knees don't get warm. Win a few lose a few

Rick G,
I was wondering. Does fuel temperature affect the richness of the mixture?
Isn't that compensated by the Motronic (or in your case the L-tronic)

Luk

Only to a VERY small degree, it's the air temp that makes a difference to performance in that cool air is denser so more can go into the cylinder which makes for a bigger bang.
The motronic does compensate for mixture with changes of temperature but the L-Jetronic has no means to do it.

there is a air temp thermistor on the intake of the afm on le-jetronic ( 2 valve systems ) systems

 

and wired as a separate entity  to the under seat computer



but no fuel temp sensor at all