Bonneville America Forums Forums Technical Forums General Tech Gas Tank Capacity

I just bought a 2006 Speedmaster and have a question about the tank capacity and mpg. I commute to work 40 miles each way and rode the Speedie to work yesterday and today. on my way home on the freeway today I had to switch to reserve at 145 miles on the odometer. This was a little worrying because I still had 15 miles to go on the freeway. My other bike is a Harley Road King, and it is EFI and has a fuel gauge, so I have never had to deal with switching to reserve before.

Does 145 miles sound about right to be switching to reserve? Also, the manual says that I have a 4.40 gallon tank and 0.92 gallon reserve. Does that mean I have a total of 4.40 gallons including the reserve or 4.40 gallons plus the 0.92 gallon reserve. I think I know the answer based on my fill up at the gas station tonight (about 3.6 gallons) but I wanted to make sure.

145 miles is about right. That's where mine hits too. Total tank capacity is 4.4 gallons including reserve. I usually just switch to reserve around 120 miles and/or get gas ASAP, though I figure I could go about 175 if I had to. I get about 42 mpg.

Hahahah, oh, dear. Yeah, well, while the results are still out on my most recent mods (140 main, 17-tooth front) I think I'm stil at about 125 before I need to hit the reserve... granted, I drive like a manaic (thereby reducing milage)... so yes, I'd say that 145 miles to the reserve is about right (and I'd guess you drive like a sane human being too, eh?)



--Jaeger

Not knowing whether your ride is uphill both ways thru gale force winds carrying 300 lbs. of gold ingots etc., it's kind of hard to say your mileage is good or bad.
But if the bike is still new and in the break-in period, anything around 40-45 mpg. is probably in the ball park.
After it is broken in and if you don't do any mods to it, you can get over 50 mpg. rather consistently with normal riding.
Once you start tinkering and modifying - all bets are off - but you should still be around the 40 mpg. range.

The most I got from a standard tank was the first day I had the bike. Topped off at a gas station across from Martin Motorsport in PA and rode 170 mile non-stop to Alexandria, VA. Picked up the machine and my wife drove the car home. I didn't think to tell her before hand to pay my tolls and stop for gas at about 100 miles.... so she didn't. At about 140 or so hit reserve. Then rode reserve until I couldn't stand it any more and finally pulled in for gas 15 miles from home, with 170 on the odo so I was getting at least 40.
I did run the tank dry once, unintentionally. Reserve got me 10 (ten) miles. I don't how it happened (well... it used up all the gas, that's how it happened). I've filled up with gas at least twice in my life so I know what a full tank looks like and was expecting at least to be able to get to a gas station 5 more miles down the road. No such luck. When you hit reserve, don't pass gas!

After having to switch to reserve unexpectedly at highway speed after only 110 miles I learned how to fill the tank ALL the way up.

The Speedmaster gets 40 MPG no matter what I do.
I tend to fill up before the 100 mile mark whenever convenient. Tonight I'll push that envelope a bit and take it to about 120 or 130 miles as a test.

I find reserve at about 130...and I'm not fanatical about getting every drop into the tank...leave it on the stand, not topping to filler rim, ect...

You usually have to switch to reserve after burning about 3 1/2 gallons of gas, so the reserve is nearly a gallon. Along with being a little safer when you are in an area with a lot of distance between stations, the reason the reserve is so big is the size and shape of the tank. To keep costs down, Triumph uses off the shelf parts as much as is practical, and they are using a petcock that is designed to have the more usual 1/2 gallon reserve with a much narrower tank.

I just cant figure it out. If I never use my reserve won't that reserve fuel get all old and stuff and not work when I need it most?


P.D.T.M.S.

It's not a separate part of the tank. Here's a pic I found. Note the ring midway on the vertical tube. The normal pickup tube is above this ring so when you 'run out' and switch to reserve, the pickup is lower in the tank. When you fill up, all the gas gets re-mixed...

I guess it could have been a real question.

P. lease
D. on't
T. ake
M. e
S. erious

Good pic though.

I have seen that there is a aftermarket petcock that is suppose to "flow" better. Any truth to that? Or use?

http://www.newspeedmaster.com/html/pingel_petcock.html

If it's anything over a TLA (three letter acronym), I am lost!

The Pingel does flow better. The only reason I changed mine was because the stocker was starting to bind...

That thing is like a Hardley price. $90. Ouch

Yeah, my apologies for the big long acronym.
I'd better start behaving before I get My Newbie butt kicked out the club.

Not really...

We have a chart and that end of it is already full.

So if the reserve is just a lower pickup in the tank, couldn't you run in reserve all the time?

Also, if the fuel petcock is left in either RUN of RESERVE when you are filling up at a gas station will that reduce the amount of fuel the tank will take on that fillup?

I've had my bike run out on me twice when I thought I had plenty of miles left and I'm thinking it might have something to do with this.

If you run in "reserve" when she spit and sputters because your out of gas...you're screwed...if your in "run" and she spits and sputters because your out of gas...flip to reserve and you got about 30-40 miles to find a gas station...

No it will not effect the ammount you can put in your tank

1. You could run on reserve all the time, but you will be SOL when you run out because there isn't anything more after the reserve is used up.

2. The only difference leaving the petcock on whilst filling the tank is that there is some chance that the variations in pressure from the fuel pumping in might force some past the float valve and flood the carburettors. For that reason only, it is a good idea to shut it off before filling.

3. Fuel consumption can vary a lot, especially with a strong headwind (natural or because you are cranking hard on the throttle). Also, you will lose up to 3/4 gallon of the full capacity if you just stop pumping the first time the nozzle shuts off. The tank is officially full when the gas is fully up to the ring at the bottom of the filler neck. You can get a little more in by rocking the bike and getting some air out of the expansion area, but you should only do this if you are going to ride right away far enough to use up the extra fuel.

Thanks for the clarification! I recall now that the gas wasn't all the way up to the rim when I didn't get the distance I thought I should have. The other times I have filled up it went right to the top and I got the extra miles.