Hi All,
My MK5 has had issues with the petrol tank cap fixing ever since I've had it. Probably due to bad storage the top of the tank mouth, has always leaked, and once or twice the cap seemed to come loose by itself. In the end, I lost the cap, and have struggled to find a replacement. The cause of the loss was a loose spigot pin in the tank mouth, which accounted for the dribble of fuel that had been occasionally seen running down the tank after a ride.
So, what to do? The suggested Harley Sportster cap needs serious modification to fit as the spring steel ears don't reach the spigots. The lack of a return on the ends, means making a new spring steel retainer of the more complicated kind detailed elsewhere in these pages, and wouldn't help with my loose spigot.
The answer, at least in my case, is the fuel cap fitted to P11 Nortons. Purists and rivet counters please look away now.
As supplied they only have two bayonet slots - see picture - and the rotating bayonet section is slightly over size.
Simply put, the fix was as follows.
Grind back the rotating portion of the P11 cap to 52mm OD approx. or a bit less.
Fill drained tank with water - most important!
Grind off and tap out two opposing spigot pins.
Weld up the two resulting holes - the material is very thin and probably a bit rusty, so great care is needed.
Dress gasket face flat.
Try the cap. I my case I needed an extra 1mm synthetic thick cork gasket on top of the red fibre one supplied with the cap. This red fibre gasket is solidly fitted to the cap so not easy to swap out. Tweak as necessary.
Drain and dry tank, refit, etc.
I shall now concoct a hinge support strap, but the cap is now a good fit, so we are back on the road.
Cheers for now
Doug
