Fuel Pump

wow that is cheep! is it after market?? or second hand??

also the oil light should come off as the engine starts up... once it has some preasure in it... or do the FZR use a level sensor rather than a preasure sensor??

 

Yes, my oil turns on when you hit the starter and also when you turn the bike off with the kill switch.As far as connecting your electrical leads you will need to find an iginition power supply and an earth terminal,this is assuming that you never had an electrical fuel pump on it before or you would just use the existing wiring. Not to sure if the pump is ment to be running all the time. If not then it may get tricky.

 

Yes, level sensor, not pressure.

 

Shouldn't you get the bike tuned to run with the pump though? *shrugs*

what psi does the fzr need to run at?

 

When i was fishing around to install my alarm i actually stumbled across the original wiring loom for the fuel pump just tucked away inside some electrical tape. Next time i pop the tank i'll have a look at the colour of the wires and maybe you could trace them from the electricals under the seat down to behind the carbys.

 

Well if the pressure of a full tank of fuel gives sufficient pressure to run the bike lets see what kind of pressure that creates;

14L of petrol / 1.35644719 (rough density of petrol) = 10.32kg
10.32kg / 9.81 = 1.051987768 N
1.051987768 N x (6mm tube) Pi/4(.006^2) = 22950.81 Pa
22950.81 Pa = 3.32873 PSI

Ok so the answer minus any friction losses in the tubes and fuel tap 3.3 PSI.

 

you are way too smart Ciaran <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s --><img src="{SMILIES_PATH}/icon_redface.gif" alt="" title="Embarassed" /><!-- s --> <!-- s:lol: --><img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" /><!-- s:lol: --> <!-- s:rofl: --><img src="{SMILIES_PATH}/icon_razz.gif" alt=":rofl:" title="Rofl" /><!-- s:rofl: --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? -->

 

to find the force the fuel excerts in Newtons, shouldnt u multiply, 10.32kg by 9.81, instead of dividing it.

i could be wrong, just inquiring

 

SORRY Ciaran, I have to shoot you down <!-- s:sniper: --><img src="{SMILIES_PATH}/icon_snipersmilie.gif" alt=":sniper:" title="Sniper" /><!-- s:sniper: -->

It is actually simpler than that.

The weight of the petrol does not come into the pressure equation, only its density and height.

10m static head of water gives 100kPa or approx 15PSI (1BAR)
1m static head of water gives 10kPa or 1.5PSI
300mm static head of water gives 3kPa or 0.45PSI (this is the approx relative head height of a full tank of fuel on a 2KR).

Since fuel is approx 75% the density of water, multiply 0.45 PSI by 0.75 and we get 0.3375PSI.

This would be approx what you get on fzr and probably similar to most other carby bikes.

Once the fuel starts flowing there will be a pressure drop thru the pipes and filters and also as the tank level gets down, hence the need to boost the pressure slightlty.


A standard generic automotive electric fuel pump which I bought from Autobarn for another project pumps about 7PSI

I hope this clears up some things.

DAVE

 

Well not for me, lol. <!-- s:rofl: --><img src="{SMILIES_PATH}/icon_razz.gif" alt=":rofl:" title="Rofl" /><!-- s:rofl: -->

Isn’t the density and height of the fuel just using a different method of calculating the exact same thing, the force? I was working off a simple pressure equation of p=F/A. So in essence the weight that I am using to get the force you have taken from what ever was used to calculate “10m static head of water gives 100kPa or approx 15PSI (1BAR)â€

 

<!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> <!-- s:o --><img src="{SMILIES_PATH}/icon_surprised.gif" alt=":o" title="Surprised" /><!-- s:o --> <!-- s:Help: --><img src="{SMILIES_PATH}/icon_question.gif" alt=":Help:" title="Help" /><!-- s:Help: --> <!-- s:roll: --><img src="{SMILIES_PATH}/icon_roll.gif" alt=":roll:" title="Rolling LoL" /><!-- s:roll: -->

 

First off I am all for making things simple, it’s like some people take pleasure in confusing others sometimes. For A in the equation I was using the area of the 6mm tube because I thought that this would be the defining factor for the output pressure of the tank. <!-- s --><img src="{SMILIES_PATH}/icon_redface.gif" alt="" title="Embarassed" /><!-- s --> The area that the force is applied must be the entire tank base and not just the pipe?

Yeah its close enough, the number I used was just inverted 1.35644719^-1 = approximately .74

I have heard comments about the tank on a 2kr being lower than the carbs as well, so I am wondering if the height of the static head should be taken from the carbs to the top of the tank and the height below being a ‘negative head’? Lowering the pressure even further?

Cheers for the info that will come in handy. It seems that the force of the fuel is being dissipated round the entire base of the tank including the pipe reducing the pressure available, so in theory if I got the exact area of the tank base and put it into the equation the answer would be the same. But your way is easier. <!-- s:mrgreen: --><img src="{SMILIES_PATH}/icon_mrgreen.gif" alt=":mrgreen:" title="Mr. Green" /><!-- s:mrgreen: -->

[/thread hijack]

 

Yes it looks as if we have got off the path a bit. And by the look of it, i think JEESH has has head rolling with all the figures.

As far as the pressure at the carbs goes, only consideration here is the height difference between the carbys float valve (atmosphere pressure at this point) and the height of fuel in the tank, once the levels are the same there will be equal pressure at each point, "0.0 PSI" hence no flow even if there is pressure at the bottom of the tank.

The 2KR would start to run lean before this point was reached and more so under heavy load (acceleration or up steep hills) leading to the possibility of melting pistons, and burning the exhaust valves.
The 2KR should not be used without a fuel pump for this reason.

DAVE

 

Well the stock one draws max .8 Amps and only produces 1.45 PSI, so yes.