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Discussion Starter #1 (Edited)
How much gas can you use with the pepcock at on? It seems I can only consume 2.8 gallons, even though the tank is supposed to be 4.2

The only think I can think up is maybe I'm not filling the tank as much as I think I am.

I was going down the road and the throttle became unresponsive in the same way it does if I drive down the road with the pepcock off by accident. I only rode 138 since last fillup. Fortunately I was close to a gas station and was able to coast up to a pump.

I didn't try using the reserve.
 

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What position is the long tab in (up or down) normally when you ride? The reserve should work, but if you're riding with reserve on then you have no backup when you run out.
 

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Discussion Starter #3
What position is the long tab in (up or down) normally when you ride? The reserve should work, but if you're riding with reserve on then you have no backup when you run out.
No, I ride with it down. I just didn't try to turn it to reserve cause there was a gas station right there.

I'm thinking I'm not filling the tank all the way up. If the reserve is designed to hold back .7 gallons, it should have been able to put 3.5 in it instead of only 2.8.

I've been refilling every 100 miles and it has been taking almost exactly two gallons. I thought 50 miles per gallon seemed to good to be true, but I just didn't know. I just hit 600 while I was riding today. This is my first bike.
 

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What bike you referring to? My 1100 hits reserve right at 140miles like clockwork
 

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Discussion Starter #5
What bike you referring to? My 1100 hits reserve right at 140miles like clockwork
V Star 650. I just expected to consume about 3.5 gallons before the main line ran out. I just open the gas cap. Even after riding 15 miles since filling it up, it still looks filled to the brim.
 

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V Star 650. I just expected to consume about 3.5 gallons before the main line ran out. I just open the gas cap. Even after riding 15 miles since filling it up, it still looks filled to the brim.
Guess if I had read the title correctly I would have known that:rolleyes:
Sorry
 

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I have just about every fill up since I bought my 650 last August.
http://www.fuelly.com/motorcycle/yamaha/xvs650a_v_star_classic/2004/nevaryzarc/232920

I tend to fill up a bit after I switch to reserve. I'm usually at 150-170 when I switch to reserve. When i'm good I usually can routinely hit 168 as my reserve is needed. I can hit 200 while on reserve, but I'm usually near enough to a gas station, I had to push one time since I really was testing it.
 

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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.
 

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Discussion Starter #11
Sounds like your main hose could be shorter than mine. I searched through a lot of old posts on this forum and apparently running out at 138 miles is not uncommon.

For the last few fillups have all equaled almost exactly 50 miles per gallon. This totally exceeded my expectations. I was second guessing myself thinking maybe I wasn't filling the tank up all the way, and tricking myself into thinking I was getting more mpg than I really was.

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.
 

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The last thing I did before I got home just now was fill the bike up.
144 on the trip clock and 2.71 Gal. went into the tank for a mpg of 53.13
By my mpg, in theory I should be able to get 223.146 mi on a 4.2 gal tank if I ran every drop out.

So yeah, I'd have to say that they just don't set the levels on those delivery mechanisms very consistantly. From what I've read, what folks can actually run out of the tank with either and/or both lines often differs wildly.

Something else you want to keep in mind is that if you fill the neck ALL the way to the top, you'll slosh fuel all over the outside of your tank through the vent as you ride away.
 

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Everyone's "tubes" are the same length. The short one is only a screen (no height). The long one is a screen raised to take suction a couple inches off the bottom. They all come out of the plastic mold the same length unless it's broken off, missing, etc. When Yamaha says a tank is 4.2 gallons they aren't talking about the usable size. They are talking about the total volume, including the reserve and the space you'll never get gas into because the tank has been designed to allow expansion. Take those two out of the equation and the motorcycle ran out of juice right on schedule.
 

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Thanks sparkn.
That makes perfect sense.
My 650 has never had anything more than fumes "in the reserve" since I bought it.
The last time I ran out of gas in the "on" position, it was @ 178 miles. At that point I got less than three miles out of the reserve.
As you described, my "long" (main) "tube" must be either broken off or missing. After I ran out in the "on" position, I couldn't hear anything sloshing around when I shook the tank.

I loosely compared the numbers...

Kyle: 138 miles on 2.8 gal = 49.28mpg. 49.28mpg X .81gal = 40 miles (approximating).
138 miles + 40 miles = 178 miles. 178 miles on 3.61gal.

Me: 178 miles on the main + 3 miles on the reserve = 181 miles. 181 miles divided by 3.61 gal = 50.13 mpg.

I used to run the thing a lot harder than I do now. That's the reason for the difference in my mpg between then and today.

If you allow a given that Nevaryzarc is probably running on approximately the same "real world" 3.61gal available in his tank... 200 miles divided by 3.61gal = 55.40mpg.
2.8gal X 55.40 = 155.40 (155.40 is, as he said, "between 150 and 170").

I'll have to tear it apart one of these days. Until then, If I remember to not push more than 168 miles between fill-ups, I'll be alright.
 

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According to the specs in my owner's manual, the reserve amount is .8 gallon which leaves 3.4 gallons under optimum conditions which probably doesn't happen. My best guess is we have roughly 3 gallons to use and this is borne out by those who list somewhere between 130 to 160 miles until reserve. I usually fill up at 120 miles on my trip meter and have only hit reserve once when I pushed it to about 150 miles.
 

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If I don't ride it hard, and keep it 5mph over the speed limit I hit 168 on my daily commutes, I am also 265+lbs so I'm running a bit heavier than most. Most of my driving is a 25 mile commute to work that is 20 miles of highway. I am usually on reserve when I gas up, and it just a matter of which side of the commute I am on when I hit the reserve switch.

If you look at my fuelly results, i've managed up to 4.09 gallons of gas in the tank, but I'm sure I was on fumes by then.
 

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Discussion Starter #18
Hit 163 today on the way home before switching to reserve. Filled up at 182 miles. Only did about 48mpg this time around.

48 MPG is still very high. So far my V Star 650 has exceeded my expectations on mpg.

Have you re-jetted your carbs or are you using the stock setup?
 

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As far as I know everything is stock. I will be going through the carbs and cleaning them this weekend or next. I bog down at 3/4th throttle.
 

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Discussion Starter #20 (Edited)
As far as I know everything is stock. I will be going through the carbs and cleaning them this weekend or next. I bog down at 3/4th throttle.
I played around with some of the brass carb screws last night after reading horror stories about them online. In case you didn't know, the screwdriver in the bike's tool bag is a JIS (Japanese Industrial Standard) and meant for the carb screws. A regular philips will strip them.
 
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