Fuel Pump System

[Donvito]

I have an 87 VR which just hit 50,000 miles.

 

I need some advice. On a recent 900 mile round trip to I experienced fuel supply issues, no fuel getting to the carbs. It would happen after being stopped usually but it happened one time while I was riding after about 60 miles of running fine. With the help of Steve Crossley (thanks Steve) I checked what I could on the road and determined the problem is with the fuel pump system. I was always able to get it running after some time and continue the ride.

 

Now that I'm home, I removed enough parts to get to the fuel pump relay. I've gone through the tests from the manual and the relay, pump and ignitor unit are all testing proper and the bike is running fine for now. I should mention that when the problem was occurring I heard a rapid clicking from behind the dashboard where the relay is located.

 

I also noticed that the relay is only sending power to the pump for about 2 seconds after turning the key on. I've read that it should be 5 seconds.

 

So, what should I do to the relay and wire connector before putting it back together? How do I tighten up the connections inside the plug? Should I clean the plugs with contact cleaner? Is the relay going bad and is there a replacement? I've searched for the relay part, Omron G86-02Y (can't find the Yamaha number and I haven't been able to find it on the parts diagrams) and I can only find a used one on ebay. Are new ones available?

 

It seems the 5 second cut off is what makes finding a replacement difficult. I know it's a safety feature for a stuck float or fuel leak but it seems to me that it's only prevents a problem with the key on and the bike not running in which case I can hear the pump. If the problem occurred while running, there is nothing to stop the pump as far as I know.

 

Thanks for any info you can provide and thanks for the prior help.

Edited March 9, 2014 by Donvito

[bongobobny]

OK the 5 seconds is arbitrary. Last I checked, a couple of years ago the relays were still available, but if I recall they were around $150. Inside the relay box is a circuit that times out until you get ignition pulses and I'm pretty sure it relies on what is known as a RC time constant which is a property of resistance and capacitance, and with time they can change. If the Fleabay relay is cheap enough it may be worth your while to take a gamble on it as opposed to the cost and availability of a new one.

 

As far as the socket goes, contact cleaner is about all you can do for it besides cleaning the relay contacts. You could try ever so slightly twisting the contacts to improve connectivity but only by a couple of degrees.

 

When is the last time you changed the fuel filter??? Also you should not hear clicking from the relay itself, only the fuel pump. The relay will only click once when you turn the key on, and one time more when spark is detected. Once energized it stays energized until you turn the key off...

[Donvito]

Thanks for the reply. Fuel filter was replaced recently. Fuel supply to the pump is good so pretty sure the problem is electrical. I know the pump clicks but the rapid clicking was from the area of the relay which made me wonder if it was going bad. I've searched for new replacements but can't find it. If you have the part number that would help. I just checked it again with the meter on it and still working fine. If I can catch a "bad" start I can definitely identify the problem so I'll leave it apart and continue checking it through the week. Thanks.