SF Fuel system

[Eveready1100]

Brad, the fuel will flow through your taps in any of the on, res, or prime positions. It's the octy valve that controls the flow.
The on and reserve feed fuel through one outlet to the vacuum controlled section of the octy valve, so will only let fuel to the carbs with the motor running. The prime position feeds fuel through the other outlet which joins the carby fuel inlet lines after the vacuum (octy) valve, so will let fuel through to the carbs at any time.
The lines could've been swapped accidently after a carb service. No biggie, unless the carb needles and seats aren't up to scratch and let fuel weep through slowly (overnight usually)
Main indication of any problems here are fuel leaking out of the bottom of the airbox.
Most of us on here have seen this symptom personally at some stage, so it's not a rare occurrence either.

[Jonesy :-)]

Hey FC
what Eddy said
+ maybe some previous owner has removed the vacuum operated diaphragm inside the tap allowing it to free flow in any position?
just thinking out loud

[XSIIE]

Hey Far,

"Guess I should just not worry about it if it all works!.
Shouldn't I ?"

Being a Gemini one part of me says;

If it aint broke, don't fix it....That way you can spend more time on it than in it.

The other side says;

If it aint broke, modify it......That way if it does brake you know how to fix it?

Either way as long as you have fun doing it.

Confused...I am...

Eddy

[Far Canal]

Had the tank off the U.S model SF today to put the new set of vacuum gauges on the carbies, really just for the hell of it to see if everything was OK. Consulting my manual with the section on SF model differences I noticed it said that fuel should not flow through the taps in the ON or reserve position without the motor running.It should only flow through the prime position not running.
This model also has an off position. Upshot of it was that fuel does flow in the ON and reserve position when motor is not running as well as the prime position(as expected).The bike still has the octopus thing in place however looking again at the manual I noticed that the 2 pipes on each petcock were the wrong way around. Anyway the carbies were close enough in sync to just leave alone. When I put the tank on again I changed the 2 pipes around on each carby to suit what the manual said, to see what would happen.......nothing different, just the same. Bike runs crisp and goes well, in fact just like a new one. Its only got a tad under 11000miles on it.
Guess I should just not worry about it if it all works!.
Shouldn't I ?
Any comments appreciated.