Is this normal behaviour?

[hardleydavidson]

Hi,

Not having ridden the bike for a few years and being a complete novice I forgot to turn off the fuel tap. The bike had been sat in the garage for a few days (missing it's air filter but with the choke on) and when I returned to it the tank was empty.

Now I know there are no fuel leaks on it, none at all, did a complete check before I put fuel in it. Is it possible for fuel to evaporate through the carb if the tap is left on?

[dynax]

There is a good chance it has leaked out somewhere, petrol can evaporate quite quickly in the open air

[Bender]

Check your oil, it may have been diluted by petrol.

[JRH]

No.

If the float in the carb has stuck open petrol will overflow from it. It could do as bender suggested by finding its way into the sump. Or it may have gone into the air filter area and evaporated.

[Mississippi Bullfrog]

If it had evaporated in a garage you'd probably smell it. So I'd double check it hasn't seeped into your sump. If so, apologies for stating the obvious, but drain the oil and replace it.

[James in Brum]

My garage smells of petrol. Hoping it is just evaporation.

[WD-40]

A float valve not seating properly or float height problem would explain your previous question about being too rich causing black spark plugs

https://www.themotorbikeforum.co.uk/viewtopic.php?f=5&t=72700