Stop The Whistle
Thanks to Jim Mann


Some Vulcans whistle. It's one of those odd characteristics that some owners find...er...charming while others find it embarassing. For those in the last camp Jim Mann has discovered both the problem (there is, in essence, a whistle built into the gas cap) and a solution.

What you'll need:

Phillips Screwdriver to remove your gas cap and take it apart
Wire cutters to snip a spring

Click Thumbnail For Larger Image

Note, this is a 'functional drawing' and is not accurate in scale or specific packaging.


Jim's Fix

There is a little black plastic valve with a spring holding pressure on it. The idea is to allow air into the tank as needed when fuel levels drop or release pressure in the tank when you stop and the hot engine expands air in the tank. If you cut one round of off the spring it will let the valve open easier and it will quit whistling.

1. Remove the gas cap assembly by removing the two screws that you see when you open the tank. Caution: There are O-rings under each screw. [Gadget note: if you skip this step you will surely drop small parts into your tank and spend hours removing tank, fuel, small parts and putting it all back together again]

2. Take the two screws off that hold the latch onto the bottom of the cap and you will see a screw holding a black plastic piece. Remove the screw and the top plastic piece (A shape knife blade or tweezers will pull it out) exposing the spring.

3. Carefully remove the spring and be careful to not loose the little black valve at the bottom of the hole. Cut off 1/2 to one round of the spring and reassemble. If the cap still whistles cut off another round. Excessive trimming will no longer hold the valve in place and could cause a fuel leak.

The venting (both directions) is through the hole that the little pointed nozzle sticks in when you close the gas cap (see drawing above) that is attached to one of the hoses you see at bottom of your bike.