looking for a more elegant solution.......

[makzy]

Bryan, I think Jeff might be on the rite track, those little diaphrams on the back of the std taps are actually little pumps that also shut of fuel flow when in pri or res position when the engine is not running, fuel taps and lines are a tricky thing to get rite, putting ordinary taps that just rely on gravity on your tank will probably cause problems, i'm actually thinkin of getting rid of mine and replacing them with somethin more modern, but if you want to keep them one solution would be to chase up some little vacuum impulse pumps from an outboard motor or generator, lots of stationary type engines have them although most these days are part of the carbie, they do a great job and will pump the fuel into the carbs no matter where you run the lines, but all that just means more pluming, and there's not much room to put stuff down there as you would know, another solution would to make up a fuel manifold block, a piece of 19 mm solid ally square about 75 mm long, drill straight through it, tap both ends to take a hose fitting, then drill 2 holes in one side to take 2 more hose fittings to run down to your carbs, mount it behind your carb diaphrams,  but you will still need to pump the fuel somehow because gravity alone won't push the fuel needles off their seats especially when the fuel is low in the tank,  and all that work really isn't necessary for a basic engine,( obviously your not runnin methenol) so perhaps just better fuel taps that have diaphram pumps would be the solution! i know the old taps can be a pain in the arse, mine are givin me grief at the moment too, but i've just ordered some rebuild kits, about 35 bucks each!!! cheers,,,,

MAX XS1100STD
Bundaberg                   

[excess.11]

Seeing as you rely on gravity to feed your carbys from the tank without the vacuum.....have you set up the tank on a level bench and propped it up as it would sit on the bike.......then open the both taps and allow fuel to run into 2 seperate containers and observe what happens at each tap at the time you say the low fuel becomes a problem?If you notice a diffence in fuel flow..i d try it again with the fuel cap open....to see if that makes a difference ,a vacuum may be forming and increasing as the fuel level drops and when you change to reserve your allowing the weight of fuel to assist in feeding the carbs again.
Also i d be interested to see if both taps provide the same volume of fuel to seperate containers to see if the flow isn t better on one to the other (ie drains faster) with the taps alone...and with your original line and filter arrangement if possible held to form and shape as it would of been feeding the carbys.It just makes sense to me to also make sure whatever and however you arrange any fuel lines........make sure they are arranged that the fuel is going all downhill.....downward pressure should by rights force the fuel to rise to the carbys......but there is the added effect of having the filters at a critical point below the fuel bowls  where they would slow down the rate of fuel .The normal arrangement of the filters on the taps and sitting in the tank have the full volume/weight of fuel in the tank to act against them and then run downhill in a standard set up...whereas the inline filters have a restricted line pressure and could provide a slower flow especially if they have to push uphill again..
Im always one for fixing a problem rather than bypassing  it .And therein would be the eternal answer.....less fuel lines and joiners......."A more Elegant Solution"

[excess.11]

Has it always been a problem since installing the different fuel tap setup?
Or........did they run ok for a while before you started getting this problem?

[AussiXS11G]

.11 mate
the problem has been for years......
diaphragms and vac hoses are a thing of the past on my machine....
the fuel taps needed linking.....
B
a little out of focus but you get the idea

[excess.11]

Brian.......was the fuel prob there before you used the carb clean? What you have done is simply bypassed the problem which is fine in the short term......but maybe you should investigate more what is causing the problem . I d swap diphrams in the fuel taps from one side to the other and see if one has nt gone hard or otherwise and the prob shifts to carbs 1 & 2 .Check that compression  hasn t been affected after using the solvent cleaner.You could simply use longer vac hoses and cross them over to determine if one has a better vac than the other....i m thinking this in conjuction with a full tank , compared to an almost empty tank , has a greater pressure on the fuel tap diaphram and assists with weight and gravity in keeping the fuel tap diaphram open.When you change to reserve your allowing the weight of fuel to again assist in keeping the fuel tap diaphram open.I see 2 areas being bypassed with the new hose set up.The diaphram in the fuel tap with the weight of fuel and gravity assisting  and the vac pressure scenario  .

[Brian]

I ran my hoses in an 'I' shape with a single fuel filter on the down pipe between carb inlets 2 & 3, she runs fine. 

[melbxs]

I also keep 2 18-inch lengths of hose in the shed, with a straight through joiner in each, so I can prop the tank up (or on the bench) for when I want to work on the carbs.

[petejw1966]

lol
thats sweet bryan, i only sent that pic cause i couldnt post
on here, but i can now.



this will give u a ruff idea, i had small rectangle fuel filters conected to the hoses
that went to each side of the corresponding petcock.

[AussiXS11G]

Pete
I have Pingle fuel taps that feed into the fuel lines as I have shown them -
so I cant really raise the tank anyway (well, far enough to remove the lines)
I use a remote tank for tuning/balancing in the workshop
B
Mate - my Nokia N900 doesn't do picture messages.... please email me

[petejw1966]

hi bryan,

i havent got the standard so not to sure,
but id put the joiner under the rubber velocity stax
the way u have it u wont be able to raise the tank as the
hoses will catch on the frame, i sent u a pic txt but not sure how
clear it is. i like to raise the tank so i can get to the mixture and sync screws.
if u dont need to raise the tank then it probably wont matter.

[AussiXS11G]

something like this will be the final solution - need to get the lengths right in-situ.....

[AussiXS11G]

Makzy
the problem does go away on reserve...
great idea to join the lines above the carbs
thanks!!

[AussiXS11G]

thx mate .... not a final .... just a bench mock up .....

[Fred]

Bryan,

I don't know if this is your final fuel routing solution but just a small point.

I think that one of your inline filters is on back the front. I imagine that like all mine that they have an arrow on the side indicating flow direction.

[makzy]

Hey Aussi, nice bit of pluming, hope it works for you but in my experience with running fuel lines down then back up you might have problems with air locks, see how you go but i'd be trying to keep the lines running down, join the two lines above the carbs then branch them out to the fuel inlets, your problem is probably elsewhere, taps or diaphrams??Does the problem still occur when on reserve?