Ewarts petrol tap reserve

............the stand pipe!

I have an orriginal  single plunger dual action tap  and as you found  its reserve capacity is only a few  miles at best .  It also has a trick up its sleeve in that it can  (under the right conditions)  use up all the reserve while still on main !. There is a slow seepage past the main position thats just enough to run weakly  at minimal throttle ( probably doing 100mpg plus ) ,so that when you do run out (on main) the tank is dry. If you are bombing along this does not happen as the flow is not enough to cope.  Its a sneaky beast , I carry a pint of fuel in the pannier which guarrantees 10 miles in eco  mode.  The 99 road test at Mira got up to 112 mpg , That must have been  a full measure of the real stuff.  

Michael is right but all that does is change the trigger point to change over.  One area that you  could also look at is, when its empty empty, is it really empty?   are you using all that is in the tank? 

One of the advantages of the pre war tanks a was the champagne glass fuel tap that had a "well" above the tap to hold the last drop of fuel.  If there is fuel left after the reserve has stopped supplying you could look at lowering the fuel tap in a spigot to make sure  you have the last drop.  Then its proper empty! 

Still extend the stand pipe a little to give you a fighting chance,   Fuel stations are not as prolific as they were...  Most cars will give you 50 miles on a yellow light, about enough to keep you out of trouble but we working with ~25% of the volume.

Cheers

Jon

These days I don't go any distance without two things. A tank bag with all the things you hope never to need plus a red 2.5 litre fuel container strapped on the back.

Pictured in a restaurant car park on a rainy day in Stirling.

Exactly.

..... to see how much difference in volume you get with different lengths. Tough to calculate, easy to measure.

I would start with a couple of inches.

My 57 99 has about 1” of reserve pipe and when I was using it for work every day it would get about 30 miles on reserve. I would sometimes forget to close the reserve side of the tap and only remembered when it ran out. My usual trick then was to push the front wheel up onto the path, or anything higher, and lean the bike over until the footrest touched the ground. This lets that last 1/2 pint of petrol from the other side of the head steady to get to the tap and was good for another 5 or so miles ridden carefully. Unfortunately 60 ish years on I couldn’t pick it back up now but fortunately I can now afford to keep it full. Happy days.

Dick