Westfield Megabusa Build Diary

25 Feb 2008
Fuel filler neck

This job was probably as scary as the exhaust manifold cutting, and a job that would ruin the same large section of bodywork if I got it wrong.

I started by taping up the fuel filler neck on the tank, as the last thing you want is a load of body dust clogging up your fuel filter and injectors.

I then covered the entire area that the hole would be cut in with masking tape, and then started marking. The way I decided to do it was to mark a cross INSIDE the bodywork which was the exact centre of the tank's filler neck. I then drilled a small hole through the centre from the inside. Now, when looking from outside you have a centre mark, so I set up my hole saw, drilled through with the drill bit, checked it was central on the inside, and then made contact with the hole cutter.

The hole is absolutely spot on and I'm absolutely delighted. That is until a few minutes later when I realise that the tank wasn't central when I drilled the hole! I break into panic thinking I've wrecked the hole thing, because there is no way the lower roll bar bolt will go in on the right hand side as the tank is too close.

There is actually a lot of room for maneuver with the hole though, so I made it larger on the left hand side, which allows the whole tank to shift over too, and the roll bar bolt fits as it should.

I was very lucky and really should have checked that the tank was central again before cutting, but it's just one of those things! Still, I got away with it...just!

All that's left is to connect the rubber hose to the tank, and then connect it to the fuel cap, but it's impossible to get the rubber hose over the tank filler neck without removing the tank, so I would advise you fit the rubber hose when you fit the tank. I had to remove the entire thing including all fuel lines to get mine on!

Once this is done it's all very simple - the hose needs clamping onto the tank and onto the fuel cap, and then the cap can be bolted down using the supplied fixings.


Tank filler neck taped up to stop it taking in dust. The hole is cut perfectly - you can see the filler neck inside the hole. I later realised the tank wasn't central, so I had to adjust the hole a little. Hose connected to extend filler neck out to the bodywork.
Fuel filler neck cap fitted. Tank feels much more secure now.