[Slider]

I was told I should turn off the gas after shutting off the engine. Is this true? Why?

[mrunderhill1975a]

In the event that your float valve has some varnish or crud which prevents it from fully closing, you would have a seep of fuel which would overfill the bowel and then leak out all over the gearbox making a puddle of fuel on the floor.  By closing the petcock you prevent this unfortunate situation.

[Merrill]

yes --if (and it will) your seal is compromised on the float valve gas can flow into
the cylinder, bad ju ju

[LotusSevenMan]

In the event that your float valve has some varnish or crud which prevents it from fully closing, you would have a seep of fuel which would overfill the bowel and then leak out all over the gearbox making a puddle of fuel on the floor.  By closing the petcock you prevent this unfortunate situation.

Sounds like you have some internal worries or you're riding too fast if you have a problem :- " that would overfill your bowel and then leak out all over the gearbox". 

'Tis true that this will prevent a problem if the carb float needle sticks due to a rust particle etc.
I had an Italian single bike with a Del'orto carb that flooded even with new parts fitted and once forgot to turn off the tap at the start of a day at college. Came out later to kick the bike over to find a cylinder and exhaust pipe full with neat twostroke fuel! Hmmmmmmmm.

[meilaushi]

Turning off the valve keeps the garage from smelling like gasoline too!

[cyrusb]

On the other hand I have never turned off the fuel tap.

[Slider]

I'll have to get used to doing that (not necessary with my Honda). It's already died on me a couple of times after taking off because I forgot to turn it back on.

[1Blackwolf1]

  It was also necessary to turn it off if you put the bike on the side stand.  Every bike I ever had leaked when put on the side stand if the petcock was left on.

[bob bezin]

i neglected to turn off the gas on a high pressure washer and the crank case filled with gas.

[cyrusb]

Funny, I have never had a problem even on the sidestand. I would think that if the carb overflowed at rest then it would be overflowing even while running. If it leaks, fix it. I do however, turn off the gas at the end of the season and drain the carb.

[hobocos]

in california you take a motorcycle class and you don't have to take the driving part of the lisence test.  In this class you are taught to turn off the gas everytime you turn off the bike.  It doesn't seem like an unreasonable habbit or unhealthy for that matter.

[Blue Ridge Wheeltor]

Leaving the gas on could result in hydrolocking your cylinder. Turn on the electric start and get a bent rod.

[Kevin Mahoney]

ALWAYS turn the petrol off when the bike is not in use. given the gravity feed, a small needle valve is all that is standing between you and a fire in your garage.

[Slider]

Okay, I'll keep doing in until it becomes habit.

Never heard of hydrolocking. Is that a cylinder full of gas?

[birdmove]

   I've ridden motorcycle for just over 45 years, and always turn the petcock to the off position when I park a motorcycle. Its really no trouble to do so, and I would way rather do that than have a vacuum controlled petcock. The vacuum controlled petcock was invented because motorcycle manufacturers didn't trust us to shut off the manual petcocks. The problem is, the vacuum controlled petcocks are the answer to a question nobody asked. They cause more problems than they fix. The only time I had to call a tow truck was because the vacuum controlled petcock went haywire on a Kawasaki EX500  in the middle of nowhere.It stopped delivering fuel, and putting it on prime didn't do it either.These petcocks require vacuum lines, and use a rubber diaphram inside which can all go bad. If you believe that simple is always better like I do, a manual petcock is just fine.And a kick starter to back up the electric starter is a great thing too.

   jon