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Zukin
21st August 2006, 13:35
Howdy

I have fitted a 15 litre long range tank to my XR (replaced the 9.5l)
I was testing it last week to see how far the reserve capacity would get me.

So when I turned the tap to reserve after the first intial cough and splutter, I thought that I would get more than the 20km until I run out of fuel :gob:
Then it dawned on me that the bigger tank goes a fair way down both sides of the frame, and that there is only provision for one tap?? So all the fuel (probably 1 or 2 litres at a guess) on the right hand side of the tank does not get picked up, the left hand side will run dry!!

Any ideas on how to fix this problem?
Is there such a thing as a long pick up hose that can go across to the other side when I switch to reserve??

I did think about the worse case scenario, and that was to tip the bike upside down :shit: :laugh:

Cheers Scott

warewolf
21st August 2006, 14:46
The 640 Adventure has a pair of small thumbscrew fuel taps, inboard at the base of each side lobe, joined with a length of hose. The LHS lobe with main fuel tap is slightly lower than the RHS.

In your case it might be simpler to fit a fuel tap on the RHS lobe. Most people probably just lay the bike on its side.

Motu
21st August 2006, 15:36
My Acerbis tank has twin taps,both with reserve,gives plenty of options.You just lay the bike down to move the fuel to the otherside,standard proceedure.But not an option for me when I had the XLV750 - if you can't pick the bike up by yourself,then it doesn't pay to do it when no one is around.

Wolf
21st August 2006, 15:36
I would have thought that the rearmost part of the tank would be low enough to allow petrol to flow from one side to the other as it empties. Looking at the pics of your bike with the new tank, it doesn't look as though the right side extends very far below the back edge of the tank, so I wouldn't think it'd hold much petrol - I could be wrong, though.

Perhaps when it goes on reserve you can pop a wheelie so the lobes are higher than the rear of the tank and allow the petrol to flow backwards and around to the left-hand side?

Zukin
21st August 2006, 15:56
I would have thought that the rearmost part of the tank would be low enough to allow petrol to flow from one side to the other as it empties. Looking at the pics of your bike with the new tank, it doesn't look as though the right side extends very far below the back edge of the tank, so I wouldn't think it'd hold much petrol - I could be wrong, though.

Perhaps when it goes on reserve you can pop a wheelie so the lobes are higher than the rear of the tank and allow the petrol to flow backwards and around to the left-hand side?

Yep thats what I intially though too, but it doesnt work like that.
If you look at the pci you will see where the frame kinda goes, so at a guess there is still quite a bit in there! :angry:

I thought of making a new pickup hose that goes across to the other side, inside the tank and connected to the tap, like a type of siphon?
Wouldnt think it would be too hard to do?

Cheers

Wolf
21st August 2006, 16:49
The question then becomes: "Why the fuck did they build it like that?" If the bottom of the tank is too low for fuel to pass around to the tap side, they should have put in a second tap and a line passing under the frame to unite the two sides or put in an internal siphon arrangement such as you suggest to bring fuel up and over the frame.

FROSTY
31st August 2006, 15:53
look at any jap bike--1170s 1990s most have the same setup more or less.
The xj 900 was a classic--My fuel gauge froze up solid one day heading up to desert road.
-saw waiuru--gas stop--hahh half tank push on the Taupo
Short version--The top part of desert road is a fucking cold lonely place to be sloshing gas from one side of a tank to the other

But to answer yput question--dude unless it deeply troubles your ZEN leave it alone. If it really upsets ya --run a pipe externaly from the left to the right side of the tank

F5 Dave
31st August 2006, 17:39
My old RD350B had a pipe from one side of the tank to the other. Was a real bear to take off as you had to pull it off, block the now draining tank with your finger while you lift the tank & then push it back on again, repeat to refit.

Two taps would be a better idea.

Wolf
31st August 2006, 19:13
My old RD350B had a pipe from one side of the tank to the other. Was a real bear to take off as you had to pull it off, block the now draining tank with your finger while you lift the tank & then push it back on again, repeat to refit.
Thank you, F5 Dave. I knew I had a bike once that had a pipe connecting the two halves that had to be removed to get the tank off but I couldn't remember which. Must've been my old RD350.

Used to have to completely drain the tank before taking it off (seems like hours through the fuel line, siphon not much better.