Fuel filler cap


Finished work early to get a few hours in on the bike. I decided to see if I could free up the fuel filler cap. I’d watched a couple of videos on YouTube to see how other people solved the problem. 

I’d watched a couple of videos on YouTube to see how other people solved the problem. Armed with this new-found knowledge, my first angle of attack was to again fill the lock with penetrating fluid.

This time I used Duck oil then left it for 20 minutes. This didn’t work. Next armed with a rubber mallet, I hit the filer cap which is supposed to help dislodge the corrosion that is sticking the locking mechanism. This didn’t work either.

 I’d seen another video which suggests picking the lock with a couple of pieces of wire & a screwdriver. This allows you to apply more torque to the lock. However, the video also suggested that there’s a good chance of breaking the lock, so I didn’t try this one. Another video suggested you may be able to gain access to the locking mechanism by accessing the underside of the tank & removing the fuel tap and low fuel sensor. This seemed a sensible approach, having a Triumph Tiger with a hand sized access panel, I thought I’d give this a go.

Off came the rear fairing again and three bolts later (it should be 4) I removed the fuel lines from the tap & lifted the fuel tank off. On to the workbench it went and as I turned it over, I could see two possible ways to access the inside of the tank. The fuel sender is too small, being only around 20mm and having removed the fuel tap, I could see this solution was a little more difficult than I thought.

There was a small amount of petrol still in the tank, although it smelled more of turpentine than petrol. By shining a torch through the fuel sender hole, I could just make out that the inside of the tank appears rusty (was hoping it wouldn’t be) but I couldn’t see the underside of the fuel filler cap. Despite that, I sprayed the inside of the tank liberally with Duck Oil and left it upside down on the bench to see if I can free the lock up that way. In the event it doesn’t work, I’ve ordered an Endoscope camera with integral LED lights I can attach to my tablet or phone to see if I can see what’s going on inside the tank.

Not much else to do on the tank but wait, so I removed the front brake callipers & pads from the bike & used the hydraulic pressure too free up the cylinders. Once side was freed up but while working on the other side, the brake fluid was pumped out of the master cylinder. No problem, I thought, just remove the cap & put some more in, I have an opened bottle somewhere which would be good enough. Of the two screws holding the master cylinder cap on, I chewed the one made of cheese & the other was firmly stuck. I’m going to have to drill them out. Bugger!

Brake master cylinder cap showing chewed screws