check the easy stuff first

This is another one of those times when I made things more complicated than they needed to be. I had a bike stalling problem that was confusing me because the symptoms didn't make sense.

This is what I sent to the HawkGT list:



Date: Mon, 18 Jun 2001 01:18:07 -0400 (EDT)
From: milktree 
To: HAWKGT-L@LISTSERV.HAWKGT.COM
Subject: dead fuel pump or carb icing or something else?


I was riding in VT yesterday and the bike was acting beautifully for
the first 300 miles or so, but then it acted like it was running out
of gas, which was odd because I still had gas in the tank.  I could
see it when I opened the gas cap.  The bike stopped on the side of
road.  no-go.  I had spark, so the only thing I could think of was
carb icing because the temperature had dropped a bunch and the
relative humidity had gone way up, and when I let the bike sit for a
while, it started right up.

But then it happened again, and again, and again, each time after a
shorter distance.

Finally, it wouldn't go, and it was late, and the battery was acting
funny for trying to start it that much (no, I hadn't flooded
the engine) 

The guy I was riding with suggested that the fuel pump had eaten
itself, as his hurricane which exibited similar symptoms was fixed
by bypassing the fuelpump.

So this is what we did.   It worked.  The bike ran perfectly the rest
of the trip home (another 60 miles or so)

When we disconected the fuel pump I ran the starter to try to empty
out the fuel remaining in the pump, and it seemed quite happy to
squirt fuel on the side of the road.  How much pressure should I
expect out of a fuel pump?  The fuel rate was plenty to make the
engine go, no question.

Could something other than a bad fuel pump have caused those symptoms?

Does running the fuel pump dry have any ill effects on it? (we didn't
disconect the fuel pump wires, just the fuel lines, that was probably
a mistake)

Could it be that the length of time it took for us to by-pass the pump
was enough time for whatever was actually wrong to sort it self out?
(warm up, cool off, drain, settle, whatever)

I believe I can use a fuel pump off a F2, is that right?  Are there
others?  anything else I should check for?


I got a bunch of responses, which included checking the fuel pump, fuel pump relay, and fuel filter. (I'm embarrased I didn't think of that one, and more embarased that I didn't check the fuel filter when I was doing regular maintainance.)

No, it wasn't the fuel pump, or carb icing, or the fuel pump relay.

It was the fuel filter. It was so filled with rust powder I couldn't blow through it. Here's a pic after I "cleaned it out" (I banged the crud out onto the floor). You can see where the convienient arrow is pointing to the crud that wouldn't come out.

Here's a couple pictures of the crud:

Once the crud was on the floor, I could then pretty easily blow through it, so I put it back together. It's not a perminant fix, but it will work fine until I get a replacement filter.

It makes me glad the filter was there, and worried about what got into my carbs on the rest of the way home.

The lesson is: Don't make it more complicated than it needs to be. fuel pump, carb icing, relays.... No! just crud!