Coming home from work today I smelled fuel.
Looked down, and on the LH side of the bike, and sure enough there's fuel pissing onto my hot exhaust!

Looking closer, at the back end of the Fuel injection pipe(?) there's a fuel pipe which snakes back in and then forward.
this pipe was leaning against the engine, and I guess after 25 years, the vibration/heat wore a hole.

the result when the engines running the fuel just pisses out onto the road.

I've looked here: and I can't find the fuel pipe listed. the closest is at the other end of the fuel injection pipe.
"Fuel hose 8x13mm part no. 16121180409

is this the right replacement part?

thanks!

Are you talking about the hose feeding the fuel rail? Is that hose #2 you are looking for?
All the hoses are under 'fuel preparation' They are also selling straight hoses by the meter.

Nope. My hose is the feed hose, at the other end of the fuel rail.
it travels in front of the ignition coil towards the centre of the bike.

are all fuel lines on this bike the same size?

this one?

I believe that all the fuel hoses are the same diameter, but some are pre-formed. If you use a straight hose, it maybe pinched when bending on tight spots

hope this pic works,
the line I'm on about is behind the one with the spring around it

That's (5) the vacuum line between the fuel pressure regulator and the throttle barrel. That shouldn't leak any petrol, otherwise your fuel regulator is shot. From the above I assume/understood you meant the hose between the aft end of the fuel rail and also the fuel pressure regulator; that would be No. 6. The fuel pressure regulator is a pain to get at as fitted on the inner side of the throttle bodies.

Oops, where did the drawing go??

ReneZ wrote:That's (5) the vacuum line between the fuel pressure regulator and the throttle barrel. That shouldn't leak any petrol, otherwise your fuel regulator is shot.

Well is was pissing fuel out and only when the fuel pump was turning. Maybe I wasn't clear, the fuel line I am on about is behind the one with the spring around it

ReneZ wrote:From the above I assume/understood you meant the hose between the aft end of the fuel rail and also the fuel pressure regulator; that would be No. 6. The fuel pressure regulator is a pain to get at as fitted on the inner side of the throttle bodies.

that's the one! exactly!

thanks!

ReneZ wrote:That's (5) the vacuum line between the fuel pressure regulator and the throttle barrel. That shouldn't leak any petrol, otherwise your fuel regulator is shot.

I will second the motion
The membrane in your fuel regulator may be cracked and leaking.

Hmmm... I'm certain it in no6 as ReneZ described,
running from the aft end of the fuel rail in behind the throttle bodies.

you can see it there in the pic, going down under the TPS

mook wrote:
I've looked here: and I can't find the fuel pipe listed. the closest is at the other end of the fuel injection pipe.
"Fuel hose 8x13mm part no. 16121180409

is this the right replacement part?

thanks!

Yes this is part # 16121180409

Thanks for your help guys!

No worries, and now you'll need to get at that regulator to replace it. "Our thoughts are with you"

I just used aftermarket high pressure fuel injection hose with no problems and no sharp bends either.

Granted the regulator is not fun to get at but a stubby screwdriver and a lot of patience will sort it out.

ReneZ wrote:No worries, and now you'll need to get at that regulator to replace it. "Our thoughts are with you"

Amen!

Hmm,
I didn't find it difficult to get at the regulator...once the filter box is out of the way there is a lot of room to work. whilst there I removed the Vacuum switch that was found unecessary by BMW and not fitted on later models. I also have removed the suction pipe (with the spring protector) and capped it off as the other three are on the advice of Ned's experience.
It may of course just be a perished fracture pipe at the fuel rail connector.
Cheers Ajays

good morning

i own an early 85 k100 rs and i got lost in that last little bit. are you saying you unhooked the fuel regulator vacuum line? i have previously removed and capped the vacuum switch for timing control as per forum concensous,but the fuel regulator?

Its being done. Some feel that the bike surges less in lower revs etc. It can't do any real harm if you want to try (just make sure you cap off the pipe on the throttle body. You might get some afterburning in the exhaust though.

well Got it sorted.

Unfortunately the replacement clip I got with the hose was the wrong size,
Luckily I didn't completely destroy the original clip, so was able to re-use it.

An absoloute PITA to loosen the clip to remove the hose, bit of finesse, bit of brute force got it done.

Seems to me either:
The original Fuel hose here was too long and therefore rubbing against the hot engine block.
or:
Someone has previously changed this hose and put too much material on there.

either way, I shortened the replacement, so it is well clear of the block.

I'd be interested to know if anyone elses hose touches the block here....