You probably already know this, but just for fun...
There is no true "reserve tank" on the 650.
There are only two pipes in the same tank. Those pipes are different lengths, so when the level of the gas drops below the upper end of the "main" pipe, the "reserve" pipe is still submerged and can suck most of the remaining gas into the petcock and on to the carb. I average about 54mpg.
BTW, I've found that a lot of systems in a lot of bikes are not set accurately. I've only got about 3 miles when I switch to reserve after damn near starving it into stalling on the main. I'll eventually take the thing apart, clean it and find out how I can adjust the height of the tubes, but in the mean-time, I'm terribly anal about filling up no later than 168 miles.
'03 650 Custom and '95 Cherry 250 Virago:
Kuryakyn Flame Grips. Chrome Covers.
Bullets w' 6.5W 350LM LED Bulbs.
Relocated Rear Signals.
Padded Sissy Bars and Luggage Racks
Lowered. Jardine Rumblers.
Re-Jetted. Corbin Stinger Seat.
Mustang Tank Strap. Large Inspire Bags.
Yamaha OEM Windshield. Purple LEDs.
Chrome Tank and Fender Trim. Eagle Embossed Fork Bag.
Classic Windshield. Mutazu LN Hard Bags w' Lights.
Last edited by 650vstar2003; 09-14-2014 at 12:51 AM.