Fuel Pump Question

Let me start out by saying I am a 125 guy, so fuel pumps are somewhat foreign to me. I have a co-worker that has an 04 CBR 600 that has sat for a while. He tried to start it today and the fuel pump won't come on. He has checked all of the fuses and connections and he suspects the pump is bad. Is there and easy way to verify if it is good or not? Can you put 12V across two of the pins to see if comes on?

 

kill switch lol

 

What's the voltage on the battery?

 

does the bike make a quiet whirring/buzzing sound for about 3 seconds when you first turn it on? make sure it's in neutral and that the kill switch is disengaged. no noise? lift up the tank, grab your electrical diagram and multimeter. find out which wire is power and which wire is ground (any old ground will work, actually) and measure voltage when bike should be priming (when first turned on or while cranking). if you see battery voltage then you've got a bad pump. if no voltage then your problem lies elsewhere.

- jim

 

Thanks Jim, that is exactly what he is looking for. He said he doesn't hear the pump come on when he turns the key. He has done all of the simple stuff, just wanted a way to be sure it was the fuel pump before he drops $350 on one for a bike he is trying to sell.

 

Yes, you can put 12v directly across the pump, keep in mind you will make a spark so make sure no fuel is present. Thats if you want to go a step further that proving out the system as above.

 

Thanks Spitz. We were thinking we could do that. I am guessing he already has the pump out so we should be able to test it in a safe manner.

 

Pump could be gummed up with varnish....

 

Thats kind of what I was thinking. Any way to clean it if that is the case?

 

Can't say about that bike but if it has screws holding it together, mark the case joints so goes back together correctly and take it apart, see what's what.

 

Ya, doesnt really prove its make enough volume or pressure, but at least you can hear/ feel it turning.

 

Sounds like taking it apart might be worth a shot. It also reminds me why i love my 125... after every weekend I take 3 minutes to pull the carb and drain it, and then dump whatever is in the fuel tank in my lawn boy. No fuel issues to worry about and it makes doing yard work a bit more enjoyable.