I have a fuel pump that doesn't seem to be working. Frst question is there a motor in the pump? I took it out and powered it on the battery, it clicks but don't hear any motor running. I have two pumps and they both do the same thing. I checked the contacts and they are like new. I don't get a relay click when I turn the key so need to trouble shoot that, but shouldn't the motor run with power applied?

 

The fuel pump always clicks when it is empty. Not always on the relay click. IIRC it has a pressure switch internally that shuts off when it reaches 6psi. You can go without the pump and gravity feed the gas direct to the carbs if needed.

Do you have a multimeter? Check for good continuity to ground and the voltage coming to the pump. The electrical system is very simple and has fuses on the left side at the front if the bike.

If you haven't yet, download the the PDF Honda manual linked in this forum. It can help you with troubleshooting.

 

I have the manual and have checked voltage to the connector on the fuel cut off relay. I get 12V on black wire to ground when I turn the key, but the relay isn't clicking when it's in there. I get 12V at the fuel pump connector also when I turn the key, so would seem like it should work. So you are saying that an empty pump powered directly will just click once and not actually run if empty? The contactor inside is clean and contacts are not burnt, and it switches when powered...I still thought I would hear the pump run tho.

The only part I haven't been able to check is the signal from the Spark Unit. I get 3.4V on the yellow/blue wire which I think comes from there.

The fuel cut off relay measures nothing across the terminals. Would have thought there would be a coil and a switch in there. If switch is normally open then that would explain no measurement there. Do you know the pin outs on that? Should I measure something on the relay?

 

If you pull the relay you can meter the coil on it. They usually run in the 1.5K+ area. The connections across for either NO or NC will be easy to test. If it is NO there will be no continuity. If it is NC there will be no resisitance. You can also provide power and ground directly to the relay's coils to test it's operation. Terminals 85 and 86 are the coil. 87(NO), 87a(NC) and 30(common) are for the relay's in and out.