Breather valve on strimmer

[ipbr21054]

I’m going to drill an extra hole in my strimmer fuel tank, fit a grommet & breather valve.
How long should the fuel pipe that enters inside the tank be ?

 

[Burnerman]

Tank breathers are fitted at the tank’s highest point, so air can get in but fuel doesn’t leak out - therefore any pipe length should be minimal. Not all machines have one and use the carburettor as a sort of pressure regulator, others use a breather in the filler cap.
Stihl for example sometimes fit a ‘beehive’ breather which is actually open to the atmosphere but well baffled to stop fuel spraying out.
John

 

[ipbr21054]

Ok minimal it is thanks.