Replacing standard fuel pump relay

This is a neat and reasonably easy way to replace the standard Honda relay with one that is switched on by the kill switch instead of the ignition unit. First you need a relay, I use automotive relays as they are easy to get hold of and fit the original relay holder.


I always solder crimping plugs when used on a bike as vibration can cause the crimp to come loose, I then insulate them with heat shrink. Honda use standard automotive cable connections so I use a three pin connector to make it as neat as possible and means it can be put back to standard in seconds if required. I also use a piggyback crimp on the live to the coils to provide the switched live so no damage is done to original wiring.


On this relay the 12v goes to pins 1 and 2 the switched live for the pump goes to 3 and 5. The neutral or earth connects to the frame earth under the seat and the 12v positive goes to the black and white wire on the coils.



If you don’t want to use the original connectors then you can cut the insulation back on the black and the white cables on the three pin relay plug and solder your cables to them instead. Any questions just ask.


Won’t this modification Defeat the Automatic Fuel Cutoff function?
I fell over once, was pin’d, couldn’t reach the bars,…

Yes, i did this mod due to having so many problems with the pump and relay. You can hear the pump run up to pressure when you turn on the ignition, if you want to keep the auto cut off for the pump then thismis not for you.

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It’s what I found during searching for fuel pump information (only german):

Notabschaltung Pierburg Pumpe (

The oil pressure switch is used for safety and you are able to fill the carbs with an extra switch.

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I suppose it’s all down to what you are trying to accomplish.
Gary’s mod ensures the carbs are always full on startup.
If you simply wish to replace the original relay and retain original function,use Gary’s method but supply the switched live to the relay coil from the blue wire that fed the standard relay,et voila(as we say in Scotland)

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Relay Schematic from a different Honda (not same but the logic is there).

This “mod” can also just be replaced by a Jumper;

Or just replace proper;

The jumper method works fine but you then have no way to turn pump off when you turn on ignition so if you are doing other electrical work the pump will be running as well which can be a bit annoying. I have a electric scott oiler that needs to be primed and also run my sat nav from the main live so don’t always want fuel pump to run.

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Not correct. Pump Power goes Off without Key, test it yourself.
As noted, the above diagram is not exact, its there for the rough circuit description.
The “relay” can also be though of as a Solid State Switch.

So the power to the black wire feeding the pump relay goes off without the key???
Not sure how the US version differs to the U.K. model but ours is a feed from fuse 5 which is live with the ignition switch on.
Anything else would negate the need for the pump relay in the first place.:thinking:

Correct, why apply this relay “mod” when a Jumper will do?
Correct, F5 powers this circuit, and F5 is power’d by the ON key.
But this “mod” deletes the Factory Fuel Cutoff Safety Feature, which should be the first sentence Warning to those who don’t realize that.
The Factory Safety Circuit is triggered from the Ignition Box, if the engine stops, the pump goes OFF.
Correct, this “mod” is not for me, I prefer to keep Safety Systems intact.

I dont use the honda ignition unit as it is prone to dry joints so the honda fuel pump relay does not work on my bike. Last time i fell off the honda the engine didnt stop anyway so the safety system is pretty poor.

Tip Over Sensor (TOS) from my V-Strom;
I’ve (unfortunately) tested it a few times, it works (with actual gravity).

Also have a Scott Oiler on it, Vacuum style, so simple.
Buddy came over with his used Strom, with the electric Scott Oiler (not working).
Left Button not working. Had to peel off the control panel face sticker and restore the silver (painted on) trace pattern.
Metal round pop plate (button) was cutting it up. Should be a Copper Clad Etch Pattern.
I paint’d ON another trace pattern, sanded disc edge, but it Will fail again.
Its always suckin electrons form the battery, 24/7 (he had a battery drain issue).
And if power is interrupted, ya has to “program” it up again (more button pushing).
How to complicate something simple.
Buddy never reinstal’d it, wants a vaccum model.
Battery drain could be from other junk festoon’d on bike.
I spend so much time Undoing damage done by previous owners (and installing Accessory Relays, Fuses, Terminal Strips, USB power outlets (Cell Phone/GPS), Waterproof Connectors, Heated Grips, PWM jacket heat controllers,…)

I’m thinking you may have confused this forum with a Suzuki Vstrom one,best if you keep your posts both on point AND accurate.
You may not either like or choose to adopt another members approach to a particular problem and that’s fine,we are all individuals here and have arrived at our own conclusions for our own reasons,so please respect that.


If you are going to fix an electrical problem you need to follow the electric diagram for the particular bike that you are working on, there is absolutely no point whatsoever using another bikes diagram to work on or explain about a different bike. All vf’s have the same diagram(electric system) or with very minor changes. From memory (experience) and reading the wiring diagram I don’t believe that the old VF’s have a TOS, unless it is buried deep in the fuel relay, so why would you want to compare a different bike from a different Manufacturer? Bif is correct, this is not a V-Strom forum. If the motor stops the relay stops the fuel pump, which means you have to switch the ignition off to cut off power to everything or hit the kill switch