A bit confused about the empty gas tank

Fuzzy

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My manual says to fill to the metal ring inside the neck. To do this pump nozzle has to be nearly out of tank. Most tanks have a high spot higher than fill point to trap an air pocket. Heat expanding the pocket of air is typically what pushed gas out of tank.

I had a Piaggio MP3 with vent in neck of tank. If filled higher than vent an air pocket would expand pushing gas to the charcoal filter and plugging it. With filter plugged tank could have vacuumn or be pressurized. A friend had his gas cap blow past his face when opening at pump. Like many I removed the filter. If tank filled too full on hot day gas would be pouring out vent line before I could pay for gas. At least it wasn’t plugging filter.
 

dduelin

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No comment on running out of gas at 3.1 gallons but I always fill up the gas tank before parking a bike that's not going to be ridden for a few days or longer. Empty air space in a tank exacerbates water condensation. I don't fill to the top of the neck when doing this, as noted leave space for heat expansion.
 

Canada369

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My NC7 was supposed to replace my MP3. I'm not sure my wife believes that anymore.

OP Afan: I wonder if you may have simply hit the kill switch with half a gallon still in the tank. Do you remember trying to restart the engine or to rock the bike to listen for gas sloshing?
 

DirtFlier

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The most I've ever put in was around 3.1-3.2 gals. I rarely, if ever, use the centerstand when filling the tank so that can make a difference in how much fuel the tank will accept.
 

Fuzzy

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It is not that hard guys. If filled according to manual it holds what the manual says. I have put 3.65 gallons in mine. Manual shows it done on center stand. I typically fill covering half the plate not all as shown in picture from manual.

03760DC2-5300-42B4-8CB6-9B30E1217862.png
 

Afan

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My NC7 was supposed to replace my MP3. I'm not sure my wife believes that anymore.

OP Afan: I wonder if you may have simply hit the kill switch with half a gallon still in the tank. Do you remember trying to restart the engine or to rock the bike to listen for gas sloshing?
The dashboard was still lit when it was coasting a bit and no sound of the engine. I tried to start it again (while coasting) but nothing happened. Although, to be honest, I didn't peek in the tank, not rock the bike.
 

Afan

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No comment on running out of gas at 3.1 gallons but I always fill up the gas tank before parking a bike that's not going to be ridden for a few days or longer. Empty air space in a tank exacerbates water condensation. I don't fill to the top of the neck when doing this, as noted leave space for heat expansion.
Dave, after I run out of gas, I was able to put only 3.17 gal. of fuel, and was expecting much closer to 3.7 gal. from specs.
 

Afan

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It is not that hard guys. If filled according to manual it holds what the manual says. I have put 3.65 gallons in mine. Manual shows it done on center stand. I typically fill covering half the plate not all as shown in picture from manual.

View attachment 42754
Hm... Never fill up over the plate. I think I would need to pull out a bit the fuel nozzle to be able to reach that level?
 

670cc

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Hm... Never fill up over the plate. I think I would need to pull out a bit the fuel nozzle to be able to reach that level?
When I fill, the pump nozzle rests on the side of the tank neck, and it is inserted only about 1 or 2 cm, and aimed at the round hole in the plate. That way I can see the fuel level as it’s rising up and then I can slow the flow rate to a trickle to top off the neck area. There is no reason to take your eyes off the tank and look at the pump display. I never user the auto shut off.
 
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76Hawke

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Hm... Never fill up over the plate. I think I would need to pull out a bit the fuel nozzle to be able to reach that level?
I usually stick the nozzle all the way in and hold it until it auto shuts off. Then, similar to 670, I will pull the nozzle out almost all the way and aim it for that little hole. It's a considerable amount of gas and would certainly explain your question.
 

Janus

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When I fill, the pump nozzle rests on the side of the tank neck, and it is inserted only about 1 or 2 cm, and aimed at the round hole in the plate. That way I can see the fuel level as it’s rising up and then I can slow the flow rate to a trickle to top off the neck area. There is no reason to take your eyes off the tank and look at the pump display. I never user the auto shut off.
I used to rely on the auto shutoff for the first part, and then I would manually top off like you describe.

Used to. It only takes one time to never trust the nozzle again. It was even at the station I frequent the most. Had to wait a few minutes for the fuel to dissipate off the back, made small talk with the Costco attendant who tried to blame me for it.
 

Jphenry

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It seems as though the discussion should be about when to respond to the fuel gage indicator. How many miles were you able to travel after the last bar started flashing. Being heavy on the throttle would give you a good reference. A double bagged E-bottle of gasoline in the hatch might be a consideration.
 

New Commuter700

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My fuel gage just changed to the last, blinking line. But it supposed to be enough to get to work, 60 miles. I was in a hurry a bit. But it was so many semis and other cars on the interstate I was a bit "heavy" on the throttle so I run out of gas before I reached my work place. Luckily I run out of gas maybe quarter mile before a gas station so I pushed it a bit. Sadly, the quarter mile had 2 "hills" I had to push - it was very hard workout! :D

But, the confusing thing was, that after I filled the tank up it showed me that I put only 3.1 gallon?!? Not 3.7.

View attachment 42706

And I'm pretty sure I run out of gas because the engine stopped working and I was coasting for next couple hundreds feet, and then the oil light went on on the dashboard.

What am I missing?
Note this post. Coupled with the fact that the most I've put in my bike is 3.2 gallons when the gauge said 0.7 into reserve and I'm not sure it will hold 3.7. But, the caveat here is that I have not run out of fuel and I could not tell you exactly how full the tank was before or at the 3.2 time. but looking through the spreadsheet it does appear that there is a discrepancy since the 3.2 showed lower mileage while the next fill-up shows one of the best. Does this add up to another half a gallon? I don't know, but I do know that I don't like pushing any bike so I try not to run out of fuel.
 
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