Afternoon all,

   I'm going to replace the fuel hoses on my k100LT soon as they are staring to split on the ends.  The amount of times the tank has been on and off also does not help.

I'm looking at this page below.

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=40&Ct=FA&SbCt=BA_15_40_FA_70&spPage=2

I get which pipe is for the in tank stuff but what about the rest?

I want to replace the lot but which one do i need for the supply from and return to the tank.

Also where does the return to the tank come from as i can't find the end of the pipe attatched to the bike anywhere?

Mike

Weird they don't say exactly what the top pipe is, but you need 8mm ID injection hose. If you want to reuse all the old jubilee clips then the 13mm OD is important, I went the cheaper route and got some from a car parts place that was slightly larger OD and a couple of the old clips just wouldn't fit. You will need around 4 feet of hose, but 5 is better in case you screw up!

The return to the tank is from the "front" or the left of the injection rail, it goes back up into the tank - that hose is covered by a thick neoprene tube for some reason.

Hi Mike!  Just did my under tank fuel lines too.  The short return line with the insulation is the easy one. The feed line goes behind the fuel rail to the

pressure regulator and can best be seen by removing the air cleaner box.
I insulated that line too ,keeps fuel tank temps down a little if that's a problem for you.

I hope this helps...

Outside of the tank hose is rated SAE 30 R8 (this is written on the fuel line).

Inside of tank is rated SAE 30 R10, (again, written on the fuel line)

I'm certain these fuel lines would be available from any good auto parts store in the UK and possibly cheaper than Motorworks.

Tomnel has a great thread for this issue , see "fuel lines"

The external fuel lines can either be 8mm or 5/16".  Make sure you get lines rated for FI systems.

to clear up some of the previous posts

on the 2 valve type motors   the fuel pressure enters from the rear most  stub on the tank to the left hand end of the fuel rail ...and exits from the right hand end ......which is different to the 4 valve per cylinder (16 valve ) systems (reverse direction )
the fuel pressure exists right upto the fuel regulator , after which the pressure drops quite markedly ..then becomes a flow situation rather than a high pressure situation .
so make sure that the lines right upto the regulator are the best you can get .

not only because the lower grades of fuel line weep fuel ( AND SMELL ) through the rubber

but also because  with the advent of ethanol additives to fuel ...you really don't know what your getting from the pump you filling from ( residue from the last pump cycle can be significant and will be delivered straight to your tank) besides what brands advertise ..local pump stations mix It up pretty good .

the insulation on the lines can be important ...not only for folks in ambient temps of 25 c or more but for anybody that gets stop start driving conditions

insulation from air conditioning systems (mostly foam based ) can be employed instead of the neoprene insulation originally fitted , and now deteriorating ...easily obtained from just about anywhere   you just need to be careful about the compression, bends etc of this type of product ...but works well  ..and cheep .

internal fuel (immersible ) fuel line is special stuff with tolerance to both external and internal fuel conditions ...and hard to find ....

good luck ...hope it works out well

On both 2V bikes and 4V bikes, the front pipe to the tank comes from FPR and the rear one goes to the fuel rail.

duck wrote:On both 2V bikes and 4V bikes, the front pipe to the tank comes from FPR and the rear one goes to the fuel rail.

have I been misled by previous posts  duck ?  quite possible I recon ... learning all the time

charlie99 wrote:

duck wrote:On both 2V bikes and 4V bikes, the front pipe to the tank comes from FPR and the rear one goes to the fuel rail.

have I been misled by previous posts  duck ?  quite possible I recon ... learning all the time

The internal plumbing of the tanks an all Ks is the same.

charlie99 wrote:

duck wrote:On both 2V bikes and 4V bikes, the front pipe to the tank comes from FPR and the rear one goes to the fuel rail.

have I been misled by previous posts  duck ?  quite possible I recon ... learning all the time

Could be that you have mixed it a bit with the fuel rail connections, Charlie?
Fuel rail input is at front on 2V's, at rear on 4V's.

that's what I thought inge ...shoot .maybe I didn't explain it well

the outlet from the tank is still the rear ...?   just the flow along the rail is the difference ?

charlie99 wrote:the outlet from the tank is still the rear ...?   just the flow along the rail is the difference ?

   Correct, Charlie.

I'm getting confused now as well.

The pipe that connects to the front of the black fuel injection rail is the one that is the rear most connection on my tank.  Should this go to the right or left hand side of the fuel injection rail thingy.

The pipe right at the front of the tank connects somewhere else but i don't know where.  This is the one i really need to change but i can't find the other end.

Mike

The line from the front tank pipe goes to the fuel pressure regulator which is bolted to the back of the throttle bodies.

The lines to the FPR have Oetiker clamps on them which can be replaced with 13mm fuel line clamps from a dealer - part 13311460928.