Fuel Pump Relay - Replacement Options?

[David Allaband]

Hello all! My fuel pump relay is bad and new ones are $200. Does anyone know a way to wire in a simple 4 or 5 prong relay? The stock FJ fuel pump relay has 6 prongs. I'm not sure what the other two prongs are for, but if someone can tell me what each of the 6 wires is for I can probably figure something out. Soldering in new leads is not a problem, and normal relays are $15.

Alternately, if anyone has a junk bike around and they want to sell me their relay for a good price I'd be happy to do that! Seems this relay is not a normal problem so junk bikes probably have them. The part number on the unit is G8D-04Y. Yamaha's part number is 42H-85740-00-00 (got that number from RPM).

To anyone who remembers me, I just got done 2 years working in China. I'm fixing up the FJ to be my daily commuter again. I have it plumbed for gravity feed fuel right now but the bike bogs down on ANY acceleration. Runs fine when I level out the throttle. On another note, after 2 years in storage I just poured gas in the tank and the bike fired right up! Didn't even need to charge the battery!

Thanks everyone!
Dave

[ct7088]

The fuel pump relay has a safety feature to stop the pump when the motor stops.
Gray wire = connection to ignition coil trigger                       no coil signal fuel pump stops
Black = Earth/Ground
Blue w Black Stripe? = Power to Fuel Pump
Red w Green Stripe = Reserve Switch
Red w Black Stripe = Reseve Switch, Engine Stop Switch(center Red/White on right Handle Bar Connector),Relay Assembly, Six Pin Digital Ignitor Connector, Pressure Sensor(Probably The Unit
                                under the carb assembly)
Green w Red Stripe = Fuel Sender Unit, Fuel Warning Light

Lots of wires and parts that could be bad insted of the fuel pump relay. From a 1991 wiring diagram.

Chris

[Pat Conlon]

Thanks Chris.

It is interesting that the fuel pump relay has an interface with the fuel sender unit, low fuel warning light and reserve switch.

[Josh.vesey]

I used one from a virago 125 i think. And it was exactley the same. Worked fine.

[Pat Conlon]

...I have it plumbed for gravity feed fuel right now but the bike bogs down on ANY acceleration. Runs fine when I level out the throttle.

David, welcome home.

On a ride, when the fuel pump acts up, it's common to bypass the fuel pump and *temporarily* run gravity feed, to get you home.
Key word being temporarily.
Without a positive fuel shut off, all you need to happen is to get a tiny piece of crud on any of your 4 float needle seats, and you will find the entire content of your fuel tank in your crankcase and on your garage floor.  

In the gravity feed mode, with the obstruction of the fuel filter and small float needles, it's not surprising that your bike bogs down.
She's starving for fuel.

Cheers

Pat

[FJmonkey]

Welcome back, one more in SoCal for possible rides and events.

[David Allaband]

Thanks for all the info everyone, especially Chris!

Here's some more information. The grounding lines (Black) for the fuel pump AND the relay are grounded well. The wire going from the relay to the fuel pump (black w blue stripe) is good, it carries current. The grey wire brings 11.8v of power to the relay. Here's the really strange thing, the relay is sending SOME power to the fuel pump. When activated the relay sends 0.3v (ZERO POINT THREE VOLTS) down the (black w blue stripe) line.

This all seems to be a good indication to me that the relay is faulty, BUT I'm not good with electricity! I'm also having trouble understanding what the other 3 lines ACTUALLY DO, or if they could somehow shut the relay down if there is a problem somewhere else.

On another note, I'm pretty sure my wiring harness is from 1990 (thought my frame and engine are 1987).

Josh, yes, I heard this relay is pretty common and on many bikes. Unfortunately there are no old bike boneyards around here.

Pat, yes, I'm unhappy about the gravity feed! I want to fix it!

Monkey, thanks! It will be good to see you guys again!

[FJmonkey]

David, check http://powaymotorcycle.com/SanDiego/used-bikes/, It may take a little searching or you could just call them. They have a lot of parts.

[ribbert]

Thanks Chris.

It is interesting that the fuel pump relay has an interface with the fuel sender unit, low fuel warning light and reserve switch.

It's a red herring!