When I first got into tigers and the lumpen could still afford to drive
them, There was a guy named "Randy Stephen" who used to show up to the
mettings at the DWP. His Tiger had a fuel leak onto the exhaust and it
caught fire! It can and will happen.
>There is usually some confusion with regard to the terms "flash point" and
>"ignition temperature". The "flash point" refers to an equilibrium
>temperature of the liquid at which temperature the vapor pressure is
>sufficient to create a combustible mixture in air. I don't have the exact
>numbers in front of me, but gasoline has a very wide range of combustible
>mixtures; more-or-less all the way between 10% and 90% I believe. If the
>lowest concentration that will burn is 10%, then the flash point is the
>minimum temperature that will produce this 10% mixture in a controlled test
>under (I believe) quiescent conditions. However, in order to ignite the
>mixture, it needs to be exposed to the ignition temperature, which is
>unrelated to the flash point and usually quite a bit hotter; i.e., a spark
>or a match, etc. Again, I don't know what the ignition temp of gas/air
>mixture is, but consider the conditions inside the combustion chamber where
>you have the ideal gas/air mixture, compressed, and in contact with some
>pretty hot surfaces, and still no combustion until the spark is fired.
>Bottom line, I wouldn't worry about the muffler itself catching the gas on
>fire. You'd need something a lot hotter, not that that isn't possible; say
>a leak in the exhaust coupled with a backfire or such.
>
>Recalling my freshman chemistry in San Diego,
>
>Bob
>
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