Bonneville America Forums Forums Technical Forums General Tech Tank reserve?

Folks,how much of the reserve on our fuel tank is never gonna get to the petcock? Old Nora Norton had petcocks on both sides of the tank so that all of the fuel that was available could be utilized(corse she didn't have a reserve).But old TBA Nora II has only one petcock,and it would seem that sure enough,some of that fuel on the right side of the tank hump ain't never gonna get used as reserve.Anybody here seen just how far we can run on the reserve?Book says we got .92 gallons of fuel reserve,but something just does not seem quite right here? Al

I'll have to look when I get home, but I think the bottom of the tank is nearly flat at the rear, so there would probably only be a few ounces of unusable gas there. The reserve on the older Brit bikes was that you only open one petcock at a time. I remember from the starting instruction book on my 650 Triumph, "Open petcock on the pretol tank, the right one by preference..." Then, when you run out, you open the left one for a reserve.

Come to think of it GB I really cannot remember if I opened up one side at a time,or both at once. Remember turning on the fuel,then pumping the Amal ticklers till fuel ran down the side of both carb's,then pushing the handle bar mounted choke on to some degree,leaning the bike over to the left,and giving her a big kick.Back in those days I was a drinker,and it could be real interesting trying to kick start Nora with a full load of beer.Stupid stupid kid, amazing I lived through those times!!! Al

As Ed suggested, there is some way that nearly all the fuel gets to the side of the petcock. During a VERY STUPID move last fall, I rode past several stations before hitting reserve. Once I'd hit the reserve level, I couldn't find a gas station anywhere. When I finally did locate one, and after removing the pucker from my a$$, I managed to pump 4.1ish gallons into the tank. Considering you can't hardly fill the darned things because of the lean angle, I'd guess I was traveling on float bowl capacity by the time I filled. I don't never made a practice of going much beyond the point I hit reserve. If I filled when I hit reserve I figured I'm OK. I never imagined I could travel as far as I did without seeing a gas station. My new way of thinking, at least on longer rides, is to fill at butt breaks even if I haven't yet hit reserve as long as about 2.5 to 3 gal will fill it.

There is a potential problem filling the tank to the max. On non-CA emissions bikes, if as much as 1/2 oz of gas manages to go down the vent hose, it will close the rollover valve at the far end and your bike starts starving in maybe 80 miles or so.
Sometimes you need the extra range, but thatt's something to be careful about.

I had the same experience with running past reserve as Pipedr did. The only difference is I didn't get to a gas station before I ran out. I went to reserve at about 160 miles. I was a few miles past a town on US-30 in Illinois. I figure with reserve I have safely got 25-30 miles. There has got to be another town on US-30 within that range. Nope!!! I fell short of Shabonna, IL by about 4 miles with the trip odometer reading 198.3. This would be just short of .92 gallons at my normal 45mpg. Fortunately a friendly farmer came along quickly and I only lost about 20 minutes on my trip time. Gotta' be thankful for good people out there. I know now that even if I just passed a town when I hit reserve, I am turning around to go fill her up.

Considering you can't hardly fill the darned things because of the lean angle,

For this reason, I fill-up while remaining seated and holding the bike upright. Interestingly (to me at least), the Bonnie tank design accounts for this as the fill port is fully upright when the bike is on the sidestand.

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Especially since there's a good chance the person fillining up next to me has a cigarette in their mouth, a cell phone in hand, and their car running while they fill. I'm more concerned with being able to drop and roll without having to hop from the bike whilst squeezing in that extra drop.

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Not to mention gasoline on the nuts!