85 VF700 Fuel Pump Relay

Hey guys,
Having the erratic fuel issues that alot of folks have experienced.
Cleaned the petcock which eliminated some variables.
Reattached with clear hose so I could see what was happening and sure enough it turns out that my fuel pump is working SOMETIMES. I was just about to buy a new generic unit when I realized it could be the relay.
I don't quite understand how the unit works, or how to test it, so thought I may as well ask for some advice.
Thanks
Mike

 

If it works like the 86 relay chuck it and jump it.

 

+1,000,000

 

Electrical is my main weakness. How can I bypass it but keep the fuel pump on?
Mike

 

Your year and model may vary, but on the '86 you just disconnect the harness side from the relay and put a length of wire between the two terminals. This will provide constant power to the pump. If it turns out that it works well this way, just tape up the connection, forget about it, and resume normal activity. There are probably a few threads around here that would have a picture.....

 

Connect black and blue/black wires at the relay plug, tape it up, and ride. After the bike sits for a day, you should hear the pump clicking as soon as you turn on the key.

 

Thanks fellas will try today

 

Look like it was the relay. Pump works solidly with the black to white jumped. Cheers for your help

 

There was a reason Honda put a relay in that pump wiring. Probably because it consumes a lot of amperage. You can buy relay kits for cheap. I was told a relay uses "small power" to control "big power". It uses a small amount of power to open and close a switch that controls the power to the fuel pump. With direct wiring it could cause excessive heat. Not a good thing around gasoline! I'd at least ask a Honda mechanic at a dealership at your earliest convenience. There must've been a reason to put a relay on there in the first place?!

 

Unless I'm mistaken, the relay is used as a safety device that only allows the fuel pump to run while the engine is running. Thus, the fuel pump will not run in the event of a crash or if he key is left on with engine off.

This is why these are often called "fuel pump safety cutoff relays" in the auto, boat, and motorcycle industries.

 

The fuel pump only runs when the 2/4 coil fires. The pump does not work 100% of the time. You can find fuel pump relays on ebay pretty cheap. I have one if you need it but I won't get back from my trip until the 16th of June or close to there.

 

It seems to be running as soon as the bike is switched on. I'll definitely monitor the heat situation, but I was under the assumption it was a safety mechanism also.
Ebay seems to have relays priced about $30, which I don't think I'm willing to pay for an untested used part. Has anyone used an aftermarket relay?
I'll totally take you up on the offer when you return if I'm not sorted by then, thanks.
Mike

 

I'm having a similar problem, how did this turn out for you?

 

From what I have read the fact that the pump only fires on the 2/4 coil it is switching on and off constantly and this is what burns the points out, imagine how many times a second the pump is on and off at 10,000rpm. Food for thought

 

Junk food cuz your assumptions are incorrect. Relay stays on until coil pulses cease but does not cycle on-and-off.

The above makes no actual sense in practical application. None !

Why run a relay when it's one more item that can fail and leave you stranded ?

After numerous problems over the years I have bypassed and eliminated the pump relay on all my Hondas without exception.

 

I can see the reason why they fit the relay because if the engine stops and the ignition is still on then without the relay the pump will keep running but at the end of the day it causes more problems than it solves so the best thing is to get rid of it and take your chances that if you do drop it you get the ignition shut off quickly. Life if full of compromises