2 wire fuel pump?

Hi chaps.
My bike wont start so checked the pump. It clicks once on pushing the starter and spurts a touch but nothing else, the fuel does not get pushed through the filter, full tank on/res etc, I presume the relay is good as there is a reaction at the pump, so I am guessing the pump is gone probably from standing so long and gummed up???
So went on ebay and bought a cheapo pump to test £19.00.
It stated it was for vf1000 s c magna but not f, anyhow frustration got to me and sent for it.
I have just noticed it has 2 wires , however as you probably know the vf1000fe has 3 wires.
Does anyone know if one wire is banked with another in this case or does it mean that the body needs to be earthed instead of using an earth wire.
Electrics not my strong point so if anyone can give some guidance I would be thankful.

Nige

Hi nige, the fuel pump has 2 wires, the fuel pump relay has 3 wires…
The fuel pump is controlled by one of the cdi units so may only pulse once on one revolution of the engine, Best thing to do to test the pump is remove the fuel pump relay and bridge the black and white wires, turn the ignition on and the fuel pump should run until the carbs are full,
P.s. the fuel is pulled through the filter, not pushed by the pump…
It is possible that the pump is sticking if it’s been stood a long time.

Pete

Thanks for the info pete,
Went into the bike cave and started testing,… I dont need a new pump or what I think a new relay.
I jumped the 2 wires like you said and got the pump to run with ignition switched on.
(yes it pulls from the filter, I was just looking at it different in my head as I was typing)
However the pump doesnt cycle when the starter is pressed, (this explains why it takes for ever to start the bike after a lay up, with empty carbs)(normally need a spray of easy start)
It does cycle when the engine is running though,
I started the bike with the wires to the pump jumped (pump cycling ok), then disconnected the jump wire (pump stops cycling), reconnected the plug from relay to pump and the pump cycles again. So why when pushing the starter with everything in normal order does it not cycle until the engine runs???
Any Ideas from you knowledgeable people??

thanks again
Nigel

The fuel pump relay is controlled by the cdi unit, the blue wire in the relay multi plug is on the same circuit that charges the ignition coil for 2 cylinders…
So 1 revolution of the engine will only charge the relay for a split second, the relay then only sends power to the pump for a split second…
If your battery is slightly down and your engine is only turning over slowly your carbs wont fill very fast, hence when the bike has been stood a long time it takes longer to start as your carb float bowls are likely to be empty…

P.s, I have in the past had a number of faulty fuel pump relays, so now I always run my vf’s with the jumper wire in

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I hear what you are saying and all makes sense, however the only fly in the ointment is that I was boosting it from my car battery and it still wouldnt draw fuel, and also when I jumped the relay it didnt start pumping until the second or third turn of the ignition , so perhaps it was sticking until it had a bit more power to overcome the gum??. and that ties into it starting to pump when the charging system was now sending power.
At the end of the day I think permanently jumping the wire as you do is the easiest way out of this.
Thank you for your help, its good to know that there is a wealth of knowledge out there to help out with these old bikes, I have even talked to bike mechanics about problems with the vf and the lads often say that they haven’t had any experience with them so its hard to comment,(and that was from the shop i bought my first vf1000 from back in 1990 ! )

cheers Pete.
Nigel

I have seen a solution with a timer relay. It powers the fuelpump for a few seconds when the ignition is switched on. Instead of bridging the relay permanently.

I wire in a parallel toggle switch for the relay on all my bikes to prime my fuel system (like after draining carbs for the winter) and to also get me home WHEN the relay fails out in the middle of nowhere.

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I think that is what I will do, seems like a good insurance mod.
thanks

It will save on battery, save on starter clutch, starter motor, save getting stuck somewhere and save on frustration when you have padded yourself out with leathers ,helmet boots etc only to stand there cursing as you sweat your bollocks off on a nice sunny day before the clouds come!

It has saved my ass twice now. Once in the middle of a floating bridge on the way out to a buddy’s cabin and once out on the river valley roads (2 different bikes). Plus saving on all the components as you mentioned. It’s SO NICE to just reach down, flip a switch, hear your pump prime everything, and have it start immediately.

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Omg right! why the fff…k arent these bikes , Na , all bikes made with such a thing!!
Seriously though I totally here you, it makes you wonder sometimes why they cant put simple fail safes on bikes or cars to that matter.
If they are so brilliant at making high tech wizardry on everything from bikes cars and toasters only for all or 1 of this stuff to fail and leave us crying in the middle of a friday night horror show they could just add a simple get out of the sh3t button.
R1s might be reliable but if they go wrong its a sad sad story.
all hail 1980s simplicity.
There done.

To fill the carb floats before starting the engine I have installed a switch to Black&White terminals of fuel pump relay. Please see attached photo.

now, I just turn the ignition, turn of fuel tap, press the switch to turn on pump until floats get full and pump stops, press switch again to turn pump off, and press engine start button for normal operation.
No more engine cranking until carbs get full :))
image

2 Likes

Great idea, I am definitely going to fit one of these.
so many times I have flattened the battery and had to leave the vf in the garage for another day because of this problem, My first vf back in 1990 never showed this as I used it every day and even when I had been on hols it would still be ok, but this one doesnt like been stood more than a few days , I always keep a can of easy start now as its the only way to get it to fire up after a week or more, but that stuff isnt good for the bores I heard.
thanks for the diagram.
cheers.

Do you put the passenger footpeg up to activate it?

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It may be an alternative way, but I don`t. I just press it :slight_smile: and keep foot peg down all the time.
I have used a simple lamp switch I had at hand. You can use any on-off switch you like.
And, you may place any switch of your choice at any place of your choice on the bike simply extending the cable to the place of your reckoning. Good Luck.