Fuel tank and tap

Fuel Tank

The tank has rusted around the knee grips where the paint has worn through.

It lacks one metal badge and the blue "Quickly" and gold "Made in Germany" decals are damaged. I took pics for reference. 

The chrome trim strip just unclips.

I cleaned de-rusted the tank as usual. The rust had left some pitting which I filled with P1000 before rubbing down again and re-painting. This gave a relatively smooth finish so I sprayed it with two coats of Halfords fuel-resistant lacquer and then refitted the chrome strip. I will fit new decals and cover these with another coat of lacquer before refitting the tap.

Fuel tap

I removed the fuel tap. There was an unholy build up of two fibre washers and sealing tape on the tank thread. The surface seemed pitted which probably explains that. I redressed it with a file to try and improve sealing.

I removed the fuel tap... Unscrews anticlockwise from tank but tap top nut unscrews clockwise from the tap body.

Tap should have two tubes giving main and reserve tanks. Both should be covered by a gauze. All was missing and what was left was blocked.

Unscrewing tap body from nut. Note its a reverse thread

The fuel pipe unscrews anticlockwise. Although it's missing, I suspect there should be another fibre washer here.

I cleaned the tap thoroughly. Remnants of the gauze I found inverted inside the tank, presumably as it had detached from the tap and been stuffed in the opening to provide some filtering effect. I will try to reinstate something but it looks like this tap now has no gauze and 2 reserve positions! There was some chipping to the mating face of the tap as well as the fuel tank, so I smoothed t at out by rubbing  it on emery paper immobilised on a flat surface. I used a copper washer in the tap which should compress between the tap and tank. I couldn't find a replacement in-tank filter so I'm going to use a disposable in-line unit.

Tank Mount

I wasn't able to get a replacement tank mount as they are in short supply. The mount is more complex than expected,. I consists of two hexagonal rubber cush mounts each bonded to a hexagon plate and joined together by a sleeve bolt arrangement. The two rubber cushions fit between the tank webs and are each secured by a bolt through the tank web and into the sleeve section. The rubber on mine had degraded on one side leaving the tank lopsided and loose. I cut another rubber hex block from a laboratory rubber bung and drilled through to allow the sleeve bolt to pass through. 

I could then drill through the sleeve bolt on that side and tap it M8 all the way through. This released the Hex plate on that side so I welded that directly to the sleeve bolt centre section. 

Home made tank mount (centre). The sleeve bolt  has been drilled and tapped continuously right through. It was then welded onto the hex base plate. The new hex rubber cut from a rubber bung is also shown.

New tank mount assembled. I will need to adjust the length of the mounting bolt (lower) so that it will retain the tank tightly but not obstruct the central thread holing the two sleeve bolts together..

I can now fit the tank and retain the new hex rubber using a longer tank mounting bolt that passes through the tank web and hex rubber, and screws into the rear of the centre section. This replaces the bonding that previously held the rubber in place. Length is critical however, as it can't foul the centre thread.

I refitted the tank using the old rank rubber cube rest. The new mount worked perfectly.

Finally I reattached the tap using a copper washer. I filled the tank with a little fuel and confirmed that it worked. I still have to install a fuel filter.