Sunday, May 26, 2013

130,509 miles

Fuel pump controller (installed in February) destroyed by gasoline

Santa Rosa, CA

Attempted to replace fuel pump upper housing

As previously noted, the upper fuel pump housing developed a hairline crack radiating from one of the screw sockets where the controller mounts. Fatigue of plastic, improper torquing, or both appear to be the cause. (Controller has been replaced numerous times.) As a result, gasoline leaked from the top of the housing, filling the adjacent controller compartment.

Several months ago, I received a used upper fuel pump housing from Frank's Motorcycles (at no charge) and finally got around to installing it. Dismantling my fuel pump, I found that despite my efforts to keep the fuel level low, gasoline had saturated the new controller and all but destroyed it (photo above.) It would soon fail.

Breather tube (capped) on replacement housing

This section of breather tube later had to be cut off

Changed out the housings, noting the two units were not absolutely identical. The replacement has a vent tube in the top that my current housing doesn't have. As seen in the photos above, I capped the vent at both ends. (Then, as I reassembled the fuel pump, I found that this tube interferes with the operation of the fuel pump level arm. I had to cut off this section of the tube.)

But after reinstalling the pump, and starting up the bike, fuel sprayed out from the hex-nut-shaped plastic just below the fuel line quick-connect (see photo below.) I immediately recognized this as a defect cited many times on Adventure Rider. The housing was defective, and was no doubt sent to me inadvertently.

Replacement housing was defective and should not have been sent

I decided to replace my original (cracked) housing), pull out a spare controller (manufactured 2004) and put everything back together. The end result: the entire fuel pump (and controller) will need to be replaced.*

Estimated cost to repair:

1 ea. Fuel pump  $481.97
1 ea. Fuel pump control unit, with gasket  $147.97

Parts total, including tax:  $680.34

*I later learned that I could probably have changed out the fitting that was leaking fuel, using that part from my old pump housing.

(This post on the BMW Motorcycle Owners of America website pretty much sums up the problems with this fuel system.)

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