fuel pump

[fj11.5]

Thinking of fitting an fj1200 fp to my84 1100, i know the needle seats should be changed ect, but what i would like to know for sure is do i need to set up the electrical side of it to cut out like the 1200, , have tried to run it battery directly and earthed,  into a 1200 carbs & tank, but even under pressure they dont stop as ive been told thats how they work, i thought before testing that the pump runs through relays ect to cut out
,and unless someone is bored and wants to bypass the pumps wiring and try it directly from the battery, then i guess a switch or 1200 pump wiring ect is the way to go

[racerrad8]

Why?

Randy - RPM

[RichBaker]

All the relay does is shut the pump off if the engine is NOT running.... There is a pressure sensor in the pump which cuts it off when the bowls are full.  Sounds like you have a bad pump, or the wrong pump.

[ribbert]

The pump simply has a constant power source through the ignition, just find any wire that is only live when ignition is switched on.
As I think Arnie said the other day, the pump turns itself off when it registers its predetermined back pressure. No relays, no electrical cut out.
The only reason it should continue to run is if it's flowing through the carbys or it's not filled with fuel.

Try putting a hose to the inlet from a fuel supply and one to the outlet, turn it on and when fuel squirts out put your finger over the end and the pump should stop.

DO NOT TOUCH FUEL PUMP WIRE TO A LIVE SOURCE AS A MEANS OF POWER FOR THE PURPOSE OF TESTING IN THE VICINITY OF ALL THAT OPEN AND SQIRTING FUEL!!!

I've seen a guy incinerated under a car doing that exact same thing, earthing it against the body ( same thing ) to test it before installing with fuel everywhere.

I assume you using the correct pressure pump, about 2-3 psi.

Noel

[Pat Conlon]

I wonder if you have thought about changing your petcock?
The engine vacuum opens your current petcock. On my '92 the fuel pump runs to pressurize the line when the ignition key is turned on, before the engine produces any vacuum, so if you have a vacuum petcock with a fuel pump and turn on the key, the fuel pump will run but not be able to get gas with the closed petcock.
A aftermarket non-vacuum petcock would work without you needing to change your tank to a '89+ which fits the proper oem petcock.
The '89+ oem non vacuum petcock will not fit on your current tank.

[FJSpringy]

wot about the vacuum operated fuel pumps that are OE on the Yamaha TDM850's apparently they slip right on to the FJ models that have fuel pumps to replace said fuel pump.

If I was going to add anything to any model FJ that's what I would use and there is no electrickery.  

[racerrad8]

Why?

Randy - RPM

As I posted regarding the petcock warning, Fuel pump conversion issues.

I still wonder...why?

Randy - RPM

[fj11.5]

why,, , just because I have a spare pump , no other reason ,, as for the petcock I also have 3 other fuel tanks from different years vacume and non vacume so no worries making something work ,, the tank on her is an 89 ..thanks randy for your excellent explanations , I new it was more than just back pressure that shuts them off , you just explained it much better than the haynes manual

[racerrad8]

why,, , just because I have a spare pump , no other reason ,,

Okay, that for letting me know. I was wondering if there was a perceived improvement of performance or something like that.

Randy - RPM

[fj11.5]

no mate, nothing exciting as that I'm afraid ,,,