[modigity]

Hello all,
I have a 2000 f4, which died at the end of last years riding season. What happened is, I started it up and went back inside the house to let it warm up. When I came back out a few minutes later, the bike was sputtering pretty bad, but still running. I hopped on and gave it some throttle, but it stalled. After that it would only fire for a few seconds, then it completely died.

Turns over just fine, and fires off starting fluid, so I ruled out electrical problems. (Changed the plugs anyways)

After going through the obvious stuff, I got into the fuel pump and filter. To rule out a clogged filter, I put a funnel into the hose that feeds the pump, after the filter. I poured in some gas, and cranked the engine over. I disconnected the hose at the 3-way just before the carbs, and no fuel squirted out when I was cranking the engine.

I also read in the service manual to test the flow of the pump, use a jumper wire in the relay (under the rear faring) to short the black/white and black/blue wires, and the pump should flow with the key turned to the on position.

Problem is, there are two black/white wires. I tried jumping both combos of black/white to the black/blue wires, and the pump didn't flow.

The only thing the pump does, is when the key is turned from off to on, or vice versa, the pump spits some fuel.

My fingers hurt

So here is my question...

I feel most likely it is the fuel pump that is the problem. But before dishing out a pretty penny for a new one, could it possibly be the fuel pump transfer relay (or power relay, not sure what its called) under the rear faring that has failed? Which is more likely to fail?

Any help is much appreciated!

Thanks, Matt

[sinfuldragon]

I would replace fuses and relays before the fuel pump, if you are wrong on the relay you aren't out near as much money and you have an extra just in case.

[modigity]

Also, is there a way to test the fuel pump? I have it off the bike.
Thanks again,
Matt

[sinfuldragon]

yeah... hook the positive wire to the pos terminal of the battery and the neg wire to the neg terminal... if it starts up its a okay if not you have found your problem

[modigity]

Originally Posted by sinfuldragon

yeah... hook the positive wire to the pos terminal of the battery and the neg wire to the neg terminal... if it starts up its a okay if not you have found your problem

Thanks dragon!
one more stupid question,
There is a green wire and a black/blue wire leading to the plastic clip, which one is positive?

Thanks again,
Matt

[sinfuldragon]

Not sure off the top of my head, easiest way to tell would be to turn the key on and use a wire tester on the clip to see what one is putting out power. Don't need a multi meter for this task, the simple tester that has a light that comes on will work wonders for this. My bike has a brown wire and a green wire... the green is neg on mine but again I would test yours with a tester to be 100%. Also don't leave the pump pluged in for a long time. If it spins up then great its working and you need to look elsewhere, its my understanding that if you leave it running with no fuel to "lubricate it" then it will burn it out. could just be hear say but better safe than sorry

[modigity]

Thanks again dragon!

Why didn't I think of that?

Your help is awesome, and if you care, ill let ya know here when I figure out what the problem is.

Lata

[sinfuldragon]

Would love to hear it. Always nice to hear the solution to a problem and it will help others in the future as well

[modigity]

OK...

I got the thing running last night.

And I don't know what the problem was...

I tested the fuel pump and it worked, although it didn't "wind up". It made a pumping/knocking sound (maybe the diaphram? I haven't taken one apart). So I hooked everything back up, and holy sh1t, it fired! It even started eaiser and ran better than before.

The only thing I can think of is maybe the connecting clip from the pump was loose. I remember it sliding apart way to easy when I was taking the pump off.

Now, when I turn the key on, the pump makes a noise, the same pumping/knocking sound as when I tested it, for a split second. It didn't do this before. Is it supposed to do this? I think it is priming the carbs.

Anyways, thanks for your help, and thank God I didn't have to buy any new parts!

[dattaway]

Its a diaphram pump. Every time you turn the key on, it will buzz for a second. If my carbs are dry, I will flick the key a few dozen times until the bowls get filled up. That's when the diaphram pump will slow and then stop. It will start clicking/buzzing/bumping again when the fuel pressure drops.

If your bike has set up for a long time and the fuel evaporated out of the carbs (two weeks) then this can happen.

[sinfuldragon]

[modigity]

Awesome. The more I learn, the more trouble I can get in. MUAHAHAHAHAHA