2 taps 2 carbs [amal]

does it matter if i run off left side , right side, or both fuel lines

No I don't suppose it does if you don't mind running out of fuel. One tap is for reserve, and that's the one, if it's not marked reserve, without the extension tube inside the mesh filter.
Cash

G'day 007, No it doesn't matter, however the right hand side is usually the "reserve" side.
The tube that goes up inside the tank, from the tap, is actually shorter on the right side, giving a "reserve" of fuel
once the level has gone below the left side.
As long as you have a "T" piece in your lines to feed both sides from either tap.
I usually "tickle" with both taps on as it seems to be faster, then turn the right side off.

If you intend to run at high speed for any sustained period, supply off one fuel tap can run the Amals low and lean. Some after market taps have been found to have a restricted flow due to a swelling of the rubber seal partially restricting the flow. Better to check the flow from the taps if you wish to run off one.

Mick

Too Right .

Triumph on forum recently , fresh engine .WHY did it burn ONE piston .

As with Methanol , where larger Float needle assys are reqd to match burn rate ,
Running continuosly past 3/4 throttle or the old ' TON ' requires adequate feed .

BOTH TAPS .

The old G.P.M. can be got with fuel into measured container , timed .
From the line attach fitting to carb, unbolted .

Grotted up filters from rusty insides can result in trouble too , the tank stand pipes
clog as does carb,
Std trick is remove tank , fit gravel , do mamba , shake out ( this bits fun ) hose out
Double and triple check , rinse with petrol , and dry in sun .

seeing as its a simlar issue :lol: Can happen with a replacement tank , of F/glass ones.

I've had my 850 starve for fuel at highway speeds, so I've adapted a habit of using both taps and keeping an eye on fuel level. But that was before I replaced the taps with the current BAP types. I'l bet it's fine now with one tap on.

BTW the reserve should be on the left side, allowing you to turn it on without taking your right hand off the throttle / brake side.

maylar said:

BTW the reserve should be on the left side, allowing you to turn it on without taking your right hand off the throttle / brake side.

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I went with this.

The original roadster tanks (69-70) didn't have a different height petcock input. If you ran out on one side, just open the other side and you had another few pints, so either side could be used as reserve. I actually like using the reserve on the LS because you don't have to take your hand off the throttle, but that's not how they marked it.

Dave
69S

Not to be contrary but there are two sides to every coin. There is no right or wrong here. I think the reserve tap changed sides from right to left in 1973. I have it where the sticker on the tank says Reserve. If the bike is dying it doesn't matter if you take your hand off the throttle to flip to reserve.

The BAP petcocks I used for a while have surprisingly small fuel orifices inside so still worth checking flow.

DogT said:

The original roadster tanks (69-70) didn't have a different height petcock input. If you ran out on one side, just open the other side and you had another few pints, so either side could be used as reserve. I actually like using the reserve on the LS because you don't have to take your hand off the throttle, but that's not how they marked it.

Dave
69S

Click to expand...

I've always figured the frame top tube divided the tank in such a way that if a tap is closed on one side that side would automatically become the reserve since the fuel on that side is really isolated from the other side of the tank when the tank level becomes low enough.

Bob

Well, All that makes sense. For a change.
I think we're onto something.