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Hi all.

A couple of days ago I wanted to change my fuel filter on my R1100S. Read a little bit about it online, and thought "how hard can it be". After I got all the fairing parts off, drained the tank, I thought... This is pretty easy. Double Jinx...

When trying to get the fuel pump and filter assembly out of the gas tank, I quickly realised why you pay professionals to do this sort of stuff... I could almost get it out, but in the end.. I said screw this and put the whole thing back together again.

Poured some fuel into the tank, and tried to fire it up. The sound the fuel pump made, when I turned the key was weird. Normally it is like a wiiiirrrrr... kinda low pitch. But now it is more like WIIIII... High pitch. And the starter just goes round and round and it won't start...

Apart from taking everything apart again, draining the tank and actually changing the filter (i've read that if you try long enough, eventually it WILL come out) What have I done wrong??? I suppose the higher pitch sound of the fuel pump is because it is running dry... But the tank is almost full, and I see no reason to why it would keep running dry after multiple attempts...

Help would be greatly appreciated!

Cheers
SVA

Is the orientation of the panel holding the fuel pump the same as when you put it back in?

The noise and lack of starting suggests the fuel pump isn't getting enough (or any) fuel. I replaced mine recently and it was a bugger to start until I properly filled it but I wouldn't recommend doing that until you're sure it's all back as it should be.

Sounds like maybe the pump is not getting loaded with any pressure. Does the whirring stop after few seconds, withignition on but engine not sstarted?

Yes. Everything is normal except for the higher pitch sound, and the fact that the motor don't start.

SVA wrote:Yes. Everything is normal except for the higher pitch sound, and the fact that the motor don't start.

Ok, how about the other extreme. Too much pressure. There will be an internal pressure relief valve to protect the pump, set higher than the pressure regulating valve. Maybe you trapped a pipe? That would kind of explain things?

It's possible ( but unlikely) that one of the fuel pipes was dislodged when you attempted to remove the filter. It is a bit fiddly but not that difficult to remove . Remedy as already noted , have another attempt . The only other possible cause I guess is that the mechanical pressure relief valve has coincidentally failed.(stuck open) Clamp the external (rubber) return pipe to see if this has an effect?
I had a similar problem to yours soon after replacing the filter and pump a while back . Cause was a poorly clamped pipe on the filter

Well... pretty embarrassing. Got the two fuel lines from the fuel pump unit mixed up, and that was what's wrong... Maybe I should stop doing things myself.

SVA wrote:Well... pretty embarrassing. Got the two fuel lines from the fuel pump unit mixed up, and that was what's wrong... Maybe I should stop doing things myself.

So the pressure feed from the pump went into the wrong side of the regulator? That would mean the diaphragm would have no chance of lifting, meaning the pump internal relief valve would kick in? And the injectors would only have the head from tank acting on them?