The V-max fuel reserve (guage) explained.

[gamorg02]

If you switch to reserve accidentally you should still get fuel. I would suggest that the electrical contact in the 'res' / 'on' switch mechanism may have had surface dirt or light corrosion on the contacts that prevented the 'res' setting being detected. By switching it multiple times you cleaned the contact and the circuit began to behave normally. (the relay may also suffer from this effect if it has not switched for some time especially on an older bike).

The fuel pump will switch off once the fuel light glows continuously for more than x seconds. I do not know what the value of x is but at startup the fuel level sensor takes about 30 seconds to stabilize.

The fuel level sensor is a 'slow' reacting switch and will take time to reach a stable switched on state i.e. low fuel light on.

If it were instantaneous the fuel relay would switch on and off every time you leaned the bike or hit a bump and the fuel level changed. You also have a limited supply of fuel in the carb float bowls that may get you and extra 100 feet down the road before the engine splutters.

hey gleno, i was re-reading this as I think you were replying to what was my first post on the forum. I actually didn't quite understand it over the summer when i posted, but also have since upgraded my vmax so its not an issue.

i do understand what you were saying now and it makes complete sense.

so basically.. thanks!

 

[Boomer]

I've been wondering, I don't see a reason I can't just leave the reserve switch in the reserve position, correct?

Then the reserve would function like basically the last 4 bikes I've owned; you get a light warning you with a gallon left, and no further action needed until you fill up. I don't think I need the be knocked upside the head by having to move a switch when the light comes on. Pretty wierd setup if you ask me.

 

[one2dmax]

Correct, It's just an electrical switch so if you aren't paying attention to your bike and it starts bucking, you look down, see the red light, switch the lever, and keep going.

Sean

 

[gamorg02]

heres the kicker tho, from what i understand...

if you leave reserve switch to RES, and don't pay attention to your lights, u may be walking the bike back.

i also think i saw buster say it, and i'm not sure if i'm reading it right, that if you are riding on reserve, once the light goes on, if u switch to 'on' it will turn the fuel pump back on... it doesn't matter the RES/ON position as logn as you switch it to the other once the light goes on... did i read that right?

 

[Buster Hymen]

heres the kicker tho, from what i understand...

if you leave reserve switch to RES, and don't pay attention to your lights, u may be walking the bike back.

i also think i saw buster say it, and i'm not sure if i'm reading it right, that if you are riding on reserve, once the light goes on, if u switch to 'on' it will turn the fuel pump back on... it doesn't matter the RES/ON position as logn as you switch it to the other once the light goes on... did i read that right?

Yes that is right. It is not like a mechanical reserve where there is an upper and lower level tube that brings in the gas.

 

[gamorg02]

Yes that is right. It is not like a mechanical reserve where there is an upper and lower level tube that brings in the gas.

i get that point.. i always thought though, with the switch being on, the fuel pump functioned until the fuel got below a certain level, as it used the fuel as a conductor for the pump. once it gets below that level RES allows you to bypass that conductor...

so if u run with reserve at all times, ran outa gas, and switched it to ON you'd really be f-ed!

 

[RagingMain]

If you run with the "Res" on all the time and are not paying attention to your idiot light you will run out of gas WITHOUT knowing you are getting low. There will be no hesitation to let you know the tank is low. Wont matter if the light comes on or not. The pump will always run in the "Res" position

If you are running in "Res" and get below the fuel sender and then turn it to "On" the fuel pump WILL shut off on you (if everything is working correctly) then you will get as far as the fuel in the bowls will take you.

Clear as mud yet???

 

[Buster Hymen]

If you run with the "Res" on all the time and are not paying attention to your idiot light you will run out of gas WITHOUT knowing you are getting low. There will be no hesitation to let you know the tank is low. Wont matter if the light comes on or not. The pump will always run in the "Res" position

If you are running in "Res" and get below the fuel sender and then turn it to "On" the fuel pump WILL shut off on you (if everything is working correctly) then you will get as far as the fuel in the bowls will take you.

Clear as mud yet???

That's not right. There is no difference between riding around in Res or On. Once the low fuel light comes on, it cuts out the fuel pump. Moving the switch to the opposite position it is in, turn the fuel pump back on.

 

[maleko89]

Buster, what Fargo said was correct? If you run in RES position all the time you'll get no warning besides the low fuel light.

 

[Boomer]

A low-fuel light, combined with the fact your odometer always reads within 10 miles every time you fill up, is enough info for me. In fact I think every bike I've owned functioned like that. You get a light with a gallon or so left. I'm just not sure why we have to have this odd switch to remind us we've got a gallon left, when two other signals are there staring you in the face!

 

[PATMAX]

Just a great big "THANK YOU" to Gleno for spelling it out to us idiot savants. I have run a KOSO RX-1 digital tach/intrument cluster for a few years with the RES on all the time. ( this means I run out of gas if I am not counting my miles) It was this way when I bought the bike. After staring at the factory manual and the Yamaha manual for hours on end, I was able to finally trouble shoot my ailment quickoly and effectively. This tach is from VMAX Bits in England from Jon. I had emailed him with no response. Now if you could explain to me how I connect the oil and water temp circuits! Gleno your beer is awaiting you in SW Florida. Sincerely, PATMAX. :clapping:

 

[vmaxpooka]

I would personally not leave the switch in the reserve position....there have been several times I have been riding on a bright sunny day and all of a sudden the thing starts to die...I have cupped my hand over the red fuel light, and sure enough its on! I guess what I'm getting at is the fact that the light is really hard to see, unless its shaded or dark. Just my thoughts.....

 

[Buster Hymen]

Buster, what Fargo said was correct? If you run in RES position all the time you'll get no warning besides the low fuel light.

Well, I know when I got this VMax I always ran it in the RES position because I read the label wrong on the switch plate. I thought RES ON meant that to the right was in reserve. So I rode it like that for over a year and always got a warning and the light. It wasn't until I joined one of the Yahoo lists that I found out I was doing it backwards! LOL! :doh:

 

[gamorg02]

Well, I know when I got this VMax I always ran it in the RES position because I read the label wrong on the switch plate. I thought RES ON meant that to the right was in reserve. So I rode it like that for over a year and always got a warning and the light. It wasn't until I joined one of the Yahoo lists that I found out I was doing it backwards! LOL! :doh:

really? wow that changes thing a bit. so once ur light would go on you'd switch over to what is actually 'run' and it'd kick the fuel pump back over again?

it seems like thats too much logic to be in the little switch or whatever.. because it'd have to know its state and then if its changed... it would also have to keep this in mind once the light went on correct then?

 

[Redbone]

really? wow that changes thing a bit. so once ur light would go on you'd switch over to what is actually 'run' and it'd kick the fuel pump back over again?

it seems like thats too much logic to be in the little switch or whatever.. because it'd have to know its state and then if its changed... it would also have to keep this in mind once the light went on correct then?

The light will come on sometime before you actually will need to thumb the switch over. I had the same misconception of how the process worked the first few months of ownership until somebody clued me in late in the summer of '07.:thumbs up:

 

[gamorg02]

The light will come on sometime before you actually will need to thumb the switch over. I had the same misconception of how the process worked the first few months of ownership until somebody clued me in late in the summer of '07.:thumbs up:

hopefully it wasn't the gas station attendent who saw u push the max in!?? haha j/k

 

[Redbone]

hopefully it wasn't the gas station attendent who saw u push the max in!?? haha j/k

Ha Ha, thankfully not. I been lucky in that regard, haven't had to push Redbone once!
I probably just screwed myself by saying that though!:bang head:

 

[gamorg02]

Ha Ha, thankfully not. I been lucky in that regard, haven't had to push Redbone once!
I probably just screwed myself by saying that though!:bang head:

hopefully u went and knocked on some wood man! (nto that kind!):rofl_200:

 

[gunrunner]

For those who have never seen the light, I suggest you take a small container of gas (1 liter or quart plastic oil bottle for example) and go ride till either the light comes one, or you actually run out.
This way you'll know for sure if your reserve sender / fuel light / fuel pump switch all work as expected, and if you do actually run out of fuel, that container will get you to the next filling station!

Great post btw Gleno, explains everything, apart from the fact that I've still never seen more than about 90 miles before my red light starts glowing! And that's doing constant speed on the highway and with a Venture diff fitted too...

Gonna have to switch my v-boost off to see if it makes a difference, I think my problem is this twitching right wrist disease I've developed since riding Maxine..

Yes its that simple , i get between 170 - 198 (best) kms before the light comes on . When i got my Max i thort **** running out of gas and took a container with me when the light went on . And now obviously if the red light shows you arent gonna give the Max **** so was just normal riding and i got 43 kms before ot run out . Now my mate services my Max what ever he does to it on tune up it seems to run like **** on choke but it does do 20-30kms per tank better than when i balance the carbs and he has had 30 yrs servicing bikes . unk::clapping:unk: