The Kawasaki ZX-12R Touring Fuel Tank
I had the idea of fitting an extra fuel tank in place of the 'under passenger seat tool box' for some time.
120 miles before looking for fuel was just not acceptable.
So now was the time.
I stripped the rear end of the bike and made a cardboard template 'dummy' tank, to see how I could get it
to fit, and also what I may have to remove from the rear subframe to make it fit.
I had started with a curved top, to follow the shape of the plastic rear seat cover,
but because of the angled sides and different length of the two curved ends,
this was not a good option, almost impossible to fold.
So I made the top flat. (which I never photographed)
I had also lengthened the wiring from the 'regulator' to the loom,
to allow myself a little more slack when re-routing the cable
The hole in the centre of the tank is for a 'two way air vent', so air can escape from the tank when being filled with fuel,
but also, so air can get back into the tank when fuel is being used.
Here you can see the fuel tank mounting brackets, which there are 6 of.
Each bracket is made from two pieces of sheet steel (0.6mm),
Welded together, and spot welded to the fuel tank.
The 'rubber mounts' I used to help stop some vibration are the same rubbers as used to hold the fairing side panels.
8mm o/d sleeved washers, with 6mm fixing bolts.
Here you can see the fuel tank inlet pipe, that will join the original fuel tank to the rear fuel tank.
The 'two way air vent' with 4/5mm bore vent pipe.
The vent pipe will need to be larger on the Mk 2 fuel tank, so 'filling up' is quicker.
This particular two way air vent did not work very well.
A new method will be developed for the Mk 2 Fuel tank, with a larger bore 'air vent' pipe (10mm)
I filled with fuel in Belgium and managed to squeeze 26.08 litres into the tank.
And travelled 259.5 miles, reading the inaccurate ZX-12R speedometer (17 tooth front sprocket fitted).
The actual mileage travelled using Microsoft Autoroute was 237.4 miles.
We were travelling at an indicated 70 to 80 mph, as my rear tyre was in very bad condition
(3500 miles, using a 2500 mile tyre), and it was wet,
so this did help with getting a very good mpg and overall distance for one tank of fuel.
I usually get somewhere in the region of 38mpg, so still an easy 200 miles per tank.