reserve gas capacity - 74 roadster - how far can you go?

[joe czech]

so I run out of gas Friday while sitting at a red light. I was a couple miles from the house, and about 5 miles to the nearest gas station. I'm sure I could have made it to the gas station, but had 5 gallons at the house, so just went home on reserve. just curious, how far TYPICALLY can one go on reserve before you really run out of gas? i'm assuming I have at least a half gallon reserve - yes/no - ??? don't know my exact MPG, but i'm guessing at least 50-60 MPG. riding 25 miles or so on reserve doesn't give me a warm fuzzy feeling and seems like that would be pushing it.

 

[kerinorton]

Depends on your setup. I only got 5 miles one time on my 750 with f/glass tank. Both my 2 Commando's have plain taps on each side and its only what s left on the l/h/s in my case. Fill up every 100 or so miles and never leave home without filling the tank. In my case I can get 150 miles on my 850 steel roadster tank. 60 mpg approx. I have run out three times on my 750 [ the last time I coasted into a servo ], but never on my 850. Once when i was too far from servos, I took a 1 ltre tin with me., and stuffed it in when I went on reserve

 

[jbruney]

You know Joe I've never checked that out before because I've always run with both taps open...... Don't believe I've ever seen that kind of mileage either... I'm more along the lines of perhaps 30-35 in my guesstimation, so continuous monitoring of gas stations has always been of major interest..... I don't like pushing nor mind stopping to top off.

 

[joe czech]

I probably really need to keep track of my MPG, make mental note, and sync it up with my odometer. I like kerinorton's filling up every 100 miles or so idea. I usually top off my tank (at home) before going out (always keep 5 gallon of non-ethanol at the house), but on this particular day I didn't top off the tank. thinking I had about 2/3 - 3/4 tank and guessing we rode about 70 miles or so, which was probably pushing it. one thing for sure, glad I had the reserve and it was less embarrassing having an e-start.

 

[L.A.B.]

just curious, how far TYPICALLY can one go on reserve before you really run out of gas?

About 10 miles, if that.

Petrol reserve tap

Ran out of fuel the other day so I switched on the reserve tap and only got 5 miles before it spluttered to a halt.I had to lean the bike right over to the left to try and get the remaining petrol in the right hand side, to the reserve tap.Then got just 2 miles.Anyone else had this problem.How...

www.accessnorton.com

 

[joe czech]

About 10 miles, if that.

Petrol reserve tap

Ran out of fuel the other day so I switched on the reserve tap and only got 5 miles before it spluttered to a halt.I had to lean the bike right over to the left to try and get the remaining petrol in the right hand side, to the reserve tap.Then got just 2 miles.Anyone else had this problem.How...

www.accessnorton.com

BINGO - that's the kind of number i'm looking for. that tells me I shouldn't rely on the reserve for anything but a pure emergency, and fill up long before I hit the reserve mark, really need to know an average MPG number so this doesn't happen again.

 

[kerinorton]

Not sure if I would rely on 10 miles. What you need to do is find out how much fuel you can get in your tank [ measure it because I once put 12 litres into my roadster 2.5 Imp gallon tank. 2.5x4.5461 = 11.36L/. Go figure. Just another one of those Norton variables. It must hold more than 12 litres as I didnt run out ] The most I have had to put into it over the last few years has been 11 litres. To me that's cutting it fine but on those occasions I was riding in company.

 

[Tornado]

This also depends on how much has sloshed from reserve side to standard side and already been consumed. Good chance reserve is never at its "full" capacity when standard depletes. I'd recommend not expecting much from reserve because of this fact.

 

[lazyeye6]

1st of all, I have difficulty comprehending that anyone is getting 60 mpg with a Commando, dual Amals or single Mikuni. If so, it must be
a very boring riding experience. I once ran out of fuel out in the wilderness and the closest gas station was 8 miles away. I went into
"limp it to the station "mode, riding at 2000 rpm in 4 th gear with very little throttle. I thought I was home free when I could see the
gas station in the distance. I ran out all of the reserve about 800' from the station and coasted to within 400' of it. I felt very lucky.

 

[johnm]

Tiny Roadster tanks is why I swapped to an Interstate tank.

The answer will also depend on what gas taps are fitted. Original style taps are available in main and reserve. The main tap has a plastic tube which prevents the last perhaps 20 mm being used. The reserve tap will drain to the bottom. And then you will get a bit more if you lean the bike over to the reserve side so you pick up the fuel on the other side of the saddle in the bottom of the tank.

With original taps I would get an extra 25 to 35 km riding normally. So indeed close to 10 to 15 miles.

 

[MexicoMike]

Ran out of gas my first day on my '71 Commando Roadster (FG tank)! On my way home, southbound on I55, bike sputtered. No worries, I had only 6-7 miles to get to my exit/gass station so I switched to reserve. About 5 miles later, it sputtered again and that was all she wrote! Pushed the bike down the interstate to my exit/gas station and filled it up. Home was another mile or so. Got home, figured they must be something wrong with the petcocks - maybe they were both reserves... So I drained the gas from the normal tap and then drained the gas from the reserve. There was less than a cup of fuel on the reserve side and the petcocks were correct! Subsequent note to self: Refuel every 90 miles!

FWIW, I have a FG tank on my 850 Fastback (converted from Roadster). On that tank I have two reserve petcocks because the way the tank is designed, once the fuel level drops to a certain point, the two halves of the tank are essentially separate. If I run out of fuel on the "normal" side, the reserve side has approximately 3/4 gallon which is (to me) a comfortable reserve.

 

[Danno]

You can always lay it on it's side to slosh the untappable reserve over to the other side.

 

[Onder]

<Tiny Roadster tanks is why I swapped to an Interstate tank.>

Eggsactly the same for me! Second time out with the whale tank I cut it too close and went on reserve.
Besides being greatly relieved that was the reason it quit, I made it 7 miles to my house. And I can tell
you that was awful close to fumes. Also remember the terrain where you ride. If you are in a hilly area you
may well be screwed. And the safety factor kicks in too. Suddenly you flame out on a narrow B road where
the speed is 60 and the locals late for an appointment you have no where to pull over and who is right will
not matter.
I wish the Commando has an trip meter like all my other brit bikes.

 

[maylar]

1st of all, I have difficulty comprehending that anyone is getting 60 mpg with a Commando, dual Amals or single Mikuni. If so, it must be
a very boring riding experience.

116.5 not boring miles on 1.92 USG yesterday. Stock '74 850 Roadster with Amals. 35-55 MPH country roads. I get better mileage at part throttle than I do on the highway.

My Garmin Zumo GPS warns me of low fuel at 125 miles. I ride with both taps on most of the time. I have done 25 miles on reserve before but that was long ago, and with different taps which certainly will make a difference.

I'd like to check exactly how far I could get on reserve, but that'd mean carrying gas with me, something I'm not equipped to do. Fortunately I live where gas stations are plentiful and even open on Sundays.

 

[concours]

Went on to reserve at 85 miles this morning. Rode 6 miles more at 75 mph.
Took 2.6 gallons.

 

[olympus]

About 10 miles, if that.

Petrol reserve tap

Ran out of fuel the other day so I switched on the reserve tap and only got 5 miles before it spluttered to a halt.I had to lean the bike right over to the left to try and get the remaining petrol in the right hand side, to the reserve tap.Then got just 2 miles.Anyone else had this problem.How...

www.accessnorton.com

Is the mileage bettered by fitting main/reserve taps to both sides...to get all available fuel out

 

[L.A.B.]

Is the mileage bettered by fitting main/reserve taps to both sides...to get all available fuel out

That would at least drain all the available fuel without having to tip the bike over.

Increasing the reserve (so reducing the main quantity) can be achieved by fitting a longer standpipe.

 

[jbruney]

I think pulling into a station regularly, about every 70-80 mi., and stimulating the local economy a bit is the best bet if one wants to keep the roadster tank. Besides a stretch, trip to the head and a drink of water prevents fatigue keeping one alert on the road.... visual inspection on an old machine never hurt either. Safety first.

 

[Lineslinger]

This is a good thread.
I replaced my leaky fuel taps during restoration and have always been curious about remaining mileage when reserve tap is opened. Some good insight regarding the different conditions and influences that affect it.

 

[storm42]

BINGO - that's the kind of number i'm looking for. that tells me I shouldn't rely on the reserve for anything but a pure emergency, and fill up long before I hit the reserve mark, really need to know an average MPG number so this doesn't happen again.

I know L.A.B's posts are always good, but, there are so many variables to this that no one can give an accurate answer, strap a can of fuel to the back and ride until you run out, then you know how far YOU can go.