Sunday, May 26, 2013

KTM Gas Cap Fix : KTM 350 EXC-F

New KTMs come with a fuel tank cap that often won't come off. It's really amazing KTM ships such a great bike with this common problem.
The problem is the button on top of the gas cap doesn't let you remove the cap sometimes. I'd heard this was often a problem, and when I picked up my new bike at the dealer yesterday I tried to remove the cap... and sure enough it didn't come off easily.

First, here are some tips if you get the cap stuck on:

  • -There are three prongs that need to lift UP to release the cap. So you aren't helping if you are pushing down on the cap when you try to remove it. You need to pull UP on the cap at the same time as pushing DOWN on the button. If the cap is really stuck get someone else to push the button while you LIFT and turn the cap
  • - Also, if you only push on the tab, that might only release the prong on that side of the cap, and if any of the three prongs stay down the cap won't release. Try removing the vent hose and push down on the center where the hose was. Don't use a using a tool to push as it is unlikely to help and will mar the cap. Just push firmly and make sure the button goes down all around, not just the tab on one side.

Summary: Remove the hose. Push down on the center where the hose is attached and watch to see the button is depressed on all sides. Pull UP on the cap while pushing down on the button. Turn the cap counterclockwise to open. Rotating back and forth (clockwise & counterclockwise) may help release the prongs if they are stuck.

Now the fixes:

  1. Some people advocate loosening the screws on the bottom of the cap (this was shown in a Tech Tip in Dirt Rider magazine). This might help... but looking how the cap is built I wouldn't recommend it as a particularly effective solution.
  2. Some guys have removed the orange three pronged widget from the cap and discarded it. Or just cut the prongs off. This results in a cap that doesn't lock on and makes the button non-functional. It may be unlikely that the cap will come loose in a fall, but I really don't like this solution.
  3. Some guys trim the corner that the prong catches on in the tank. This could be a bit scary, as you don't want to drop any bits into the tank or accidentally cut your tank too much. However, it is a really good idea to inspect that corner to make sure a deformation or bit of scarf isn't holding up the release of the prongs.
  4. My choice was to modify the prongs on the cap. This should work the same as modifying the tank, and if something goes wrong you have only hurt the gas cap. (Worse case is you just end up with fix #2.) I did the mod by removing the orange widget from the cap, trimming it, and then re-assembling the cap.
Here are some pics of the modified prongs. I did this carefully by removing the widget and shaving it with a sharp exacto knife. This cut corner makes a "ramp" that helps the prong get over the corner it catches on. Done carefully, the cap still latches but the button more easily releases the prongs so the cap can be opened.

Rumor has it KTM has changed the caps for 2014... we will see!