Fuel tap pipes

[jamesrm]

Hi guys, just trying to work out why my NC30 uses so much fuel and have come across this pipe from the fuel tap which appears to go nowhere, but has been destroyed and sealed up by heat damage from somewhere.
Any ideas if its supposed to go anywhere? or do i just need a replacement bit of pipe?
Many thanks James

[Neosophist]

vaccum hose. it should connect to the vaccum pipe on the cylinder

perhaps your tap has been modded becuase you shouldnt get fuel flow without it being connected.

what kind of fuel consumption are you getting now? where is your bike / how is your bike being ridden.

what have you done to check it so far? tyre pressure / binding brakes / chain

[arsey30]

Hose not required, that is just the tap breather inlet/outlet.
The vacuum hose goes on the forward facing tap stub, the other end onto the cylinder head screw in spiggot.

They use lots of fuel, I would not worry if I found no leaks, and the bike went well.

If that [not required] hose is blocked, then fuel flow may be reduced.

[jamesrm]

Thanks for the replies!

I will throw the pipe away in that case, the vacuum hose is still present I just had it disconnected in the picture.

The fuel consumption is pretty bad, i got around 60 miles to around 12 litres, however the rear brake does bind slightly at times and is used in London.

I wonder if its over rich, it doesn't seem to need much choke to start (choke lever on carb appears to move freely) which I have read is not normal for these bikes and smells of fuel quite a bit at idle.
But on the flip side does seem to ride pretty well albeit with a flat mid range.
Maybe time to take the carbs off and have a look whats inside.

Cheers James

[arsey30]

Fuel smell at idle will not give high consumption on the road, nor will amount of choke for starting.

Make sure no flooding or fuel leaks.
Flat mid range is a common set up, weak for emissions test.

Ride it on open roads to see if it revs and pulls OK, if so, go on your way rejoycing.

[Neosophist]

Hose not required, that is just the tap breather inlet/outlet.
The vacuum hose goes on the forward facing tap stub, the other end onto the cylinder head screw in spiggot.

They use lots of fuel, I would not worry if I found no leaks, and the bike went well.

If that [not required] hose is blocked, then fuel flow may be reduced.

That'll teach me for englarging the picture :D

yep its the vent, i dont think they had a hose there as stock.. maybe somebody put it on to bodge a leaking diaphram?

that sounds pretty poor in mpg.. are the plugs black? air filter stock? how does it run.

I get about 125 miles to a tank of spirited riding.

[iDemonix]

As above, no point in it, get rid.

Just an idea, are you running standard sprockets? I've changed mine for better acceleration but this throws the speedo out and could make you think your MPG is not what it is. (Also I get less MPG for the sprocket change).