hotwheels22
New member
hi kurt, all,
i'm prepping for a west texas trip and i am changing out petcocks and would like to measure my reserves. i had a pretty good thread that explained how to do this but it left out some steps and since i don't exactly understand how these work in conjunction with the petcock "straws" i am hoping someone will help me out.
i'm guessing here but since i don't really understand this i'm hoping someone has a link or a better explanation:
1. change out to new petcocks since these (height of straws?) can affect amount of reserve.
2. fill tank with fuel to a point at which one or both petcocks turned to ON position and has fuel flowing.
3. turn right petcock to RESERVE and drain out. measure amount.
4. turn left petcock to RESERVE and drain out. measure amount.
does this sound like it is sufficient?
-
longer question (since i'm interested in knowing how this works with the straws):
anyone understand exactly how the straws on the petcocks work in the actual tank?
as i understand it my tank has a "dividing line" down the middle with a reserve on the right side of the tank and a reserve on the left side of the tank. reserve on the right is located higher up in the tank (?) and it just happens based upon the geometry to have less (?) reserve while the reserve on the left is located lower in the tank and it just happens to have more reserve - basically solely based upon the geometry of the tank, is that right?
and standard operating procedure seems to be to turn on the right reserve, use it up, then turn on the left reserve and use it up (assuming you are not on the highway or going to be merging in traffic). in this way both carbs get fed through the crossover and you have an extra reserve (or reminder) in the left reserve in case you don't get to a gas station on the first reserve?
so - when you turn the right petcock ON - it is 'sipping' from the tall straw and catching all fuel that is above this level. and then in the case of both petcocks being ON, you are catching all the fuel at the lowest level of the pair of tall straws is that right?
then when the fuel gets below this level - which i am guessing /could/ be at a height above where the reserves are "cut off" by the "dividing line" in the tank - you would turn the right petcock to RESERVE and it would basically sip up any fuel that is above the cutoff for the right reserve and when this is done it would start using up just the right reserve fuel. then turn on the left to RESERVE and it uses up all of its reserve tank?
if so, doesn't this mean that taking a measurement by turning on the right RESERVE /first/ will show more fuel in the right "reserve" and conversely turning on the left RESERVE first will show more fuel in the left RESERVE?
i mean, i realize that the total amount would be the same in both cases but is it the case that by turning on the right RESERVE first give you some amount and then turning on the left RESERVE will give you the ACTUAL reserve in the left side of the tank. and then conversely turning on the left RESERVE first will give you some amount and then when this is used up you turn on the right RESERVE and this tells you the ACTUAL amount left in the right RESERVE?
i know this is not consequential for slab riding or riding in the city but in west texas you don't have a lot of gas stations (with some closed on sunday or even saturday) and even if you look on a map and it tells you that you have some amount of miles to get to the next station that the topography is so steep in some areas that you may actually be getting a great deal less per mile than you would on a normal straight slab.
anyway, i'd love to at least make sure i understand how much i have in the reserves (and how they work) so in case i have to loan out fuel at least i do it with the understanding of how far i can get with what i have in the tank.
THANKS in advance for any good solid info on this.
- jon
1993 r100gs BMW
i'm prepping for a west texas trip and i am changing out petcocks and would like to measure my reserves. i had a pretty good thread that explained how to do this but it left out some steps and since i don't exactly understand how these work in conjunction with the petcock "straws" i am hoping someone will help me out.
i'm guessing here but since i don't really understand this i'm hoping someone has a link or a better explanation:
1. change out to new petcocks since these (height of straws?) can affect amount of reserve.
2. fill tank with fuel to a point at which one or both petcocks turned to ON position and has fuel flowing.
3. turn right petcock to RESERVE and drain out. measure amount.
4. turn left petcock to RESERVE and drain out. measure amount.
does this sound like it is sufficient?
-
longer question (since i'm interested in knowing how this works with the straws):
anyone understand exactly how the straws on the petcocks work in the actual tank?
as i understand it my tank has a "dividing line" down the middle with a reserve on the right side of the tank and a reserve on the left side of the tank. reserve on the right is located higher up in the tank (?) and it just happens based upon the geometry to have less (?) reserve while the reserve on the left is located lower in the tank and it just happens to have more reserve - basically solely based upon the geometry of the tank, is that right?
and standard operating procedure seems to be to turn on the right reserve, use it up, then turn on the left reserve and use it up (assuming you are not on the highway or going to be merging in traffic). in this way both carbs get fed through the crossover and you have an extra reserve (or reminder) in the left reserve in case you don't get to a gas station on the first reserve?
so - when you turn the right petcock ON - it is 'sipping' from the tall straw and catching all fuel that is above this level. and then in the case of both petcocks being ON, you are catching all the fuel at the lowest level of the pair of tall straws is that right?
then when the fuel gets below this level - which i am guessing /could/ be at a height above where the reserves are "cut off" by the "dividing line" in the tank - you would turn the right petcock to RESERVE and it would basically sip up any fuel that is above the cutoff for the right reserve and when this is done it would start using up just the right reserve fuel. then turn on the left to RESERVE and it uses up all of its reserve tank?
if so, doesn't this mean that taking a measurement by turning on the right RESERVE /first/ will show more fuel in the right "reserve" and conversely turning on the left RESERVE first will show more fuel in the left RESERVE?
i mean, i realize that the total amount would be the same in both cases but is it the case that by turning on the right RESERVE first give you some amount and then turning on the left RESERVE will give you the ACTUAL reserve in the left side of the tank. and then conversely turning on the left RESERVE first will give you some amount and then when this is used up you turn on the right RESERVE and this tells you the ACTUAL amount left in the right RESERVE?
i know this is not consequential for slab riding or riding in the city but in west texas you don't have a lot of gas stations (with some closed on sunday or even saturday) and even if you look on a map and it tells you that you have some amount of miles to get to the next station that the topography is so steep in some areas that you may actually be getting a great deal less per mile than you would on a normal straight slab.
anyway, i'd love to at least make sure i understand how much i have in the reserves (and how they work) so in case i have to loan out fuel at least i do it with the understanding of how far i can get with what i have in the tank.
THANKS in advance for any good solid info on this.
- jon
1993 r100gs BMW