Turning off Gas

[birdmove]

This confusion on gas "petcocks" can be excused due to the fact that very new riders may never have been exposed to the earlier petcocks that were , and are, gravity fed, engine vacuum having nothing to do with fuel supply on those bikes. Since I'm 57 years old and started riding at eight, almost every motorcycle I've owned has had a gravity fed petcock. With the gravity fed one must develope the habit of twisting the lever on the petcock to the off position when parking the bike. The reason being, that if the needle and seat develope a leak, possibly due to a little piece of dirt, the gas will continue to fill the float chamber, and then will overflow and continue leaking.

But, don't get the idea that vacuum controlled petcocks are trouble free-they most certainly are not! Check that subject of a Suzuki DR200 thread at, say, advriders.com, and you will see that the vacuum petcocks are known to develope leaks and fill the cranckcase with raw gas. Many owners of those bikes replace the vacuum petcocks with gravity ones and simply turn them off when parked. Many DR200 owners even replace the OEM petcock with a gravity fed before any problem developes. Dual sport bikes are often way off the beaten path and owners need to be pretty self sufficient-many dual sport riders are set up to fix a flat on the trail, because noone is going to find them and haul their bikes out to the road.

I prefer a gravity fed petcock any day due to simplicity-just turn it to off when parked and you won't have a problem. The Royal Enfield Bullet still used a gravity fed petcock right up until the new fuel injected model came out. There are other motorcycles still using the gravity fed units also.

Jon