Cracked petrol tank fitting

[ahebron]

SWMBO's 2000 F650GS started to leak fuel from under the seat yesterday. We went for ride over The Rimutaka Hill

http://www.youtube.com/watch?v=EhKBQU40e0o

and when stopped for a 'wee' moment I noticed her bike doing the same when on its side stand. A quick look under the seat showed the fuel pump mount full of petrol . I told her we might as well keep riding to use the petrol in the tank and lower the level. After a lovely ride through Southern Wairarapa we headed back home. Once in the garage I had a look and found it had a crack right across the unit and next to the return pipe.
Today I called into the local dealer to get a price and availablity, ex Auckland and NZ$906.00 but an email when I got home found that price wrong it is NZ$560.00 still .
So what caused it to crack and what are my options. Possibly the seat is pressing down on the return pipe and deforming the unit till it cracked or its a crap piece of equipment.
Option one is to fit a new one but only as a last resort.
Option two is get a second hand one but it probably do the same thing
Option three get a piece aluminium or steel and machine a new part in the lathe and mill it to do the same job, I would have to weld on lugs to mount the pump brackets that I would cut off the original and fit brass pipe fittings to get fuel in and out. Only mounting the electrics is causing a bit of head scratching at present. I would have to get this powder coated to stop corrosion from moisture in the tank.
To be honest I like a challenge so am tending towards option 3 but does anyone have any other ideas or reasons not to do it.

Thanks
Adrian

 

[komatias]

Well documented mode of failure, check on the F650.com website for more info.

 

[john_aero]

get onto motorworks in uk, they will have a 2nd hand tank and wont screw your for it wither.

http://faq.f650.com/GSFAQs/FuelTankFAQGS.htm

check frame number and see if the service bulletin was done or if it needed be done.

seems be the older single spark models from USA that suffered it

 

[ahebron]

Got it sorted
I started with this

And turned it down to this

Added these

And these


To get the ridges on the fuel pipe fittings I silver soldered a ring of 0.8mm mig wire to the pipe. When doing bigger pipes I use a ring of welding wire.


Adrian

 

[ahebron]

Wired up this

Had it cadmium plated then added a nice coat of black paint

But the paint reacted with petrol so I had to remove it. The red paint in the picture is etch primer where the cadmium plating didn't.


And it doesnt leak and I would be very surprised if this one cracks.
As you can see I cut the pump etc from its original fitting and bolted it to the new fitting. If I get the old one plastic welded I can also refit the bit I cut off.
The socket for the pump and fuel level light is off a Toyota STI 90, whatever that is.
All up costs
125mm x 45mm steel from Tata Steel including post NZ$35, Plug to connect to loom NZ$10, bad cadmium plating NZ$40 (minimum charge).
Considering I was originally quoted NZ$900.00 then NZ$530.00 I reckon my job for under NZ$100 is a bloody good one.
And it was fun to make

Adrian