Some of the units in the ranges are supplied with a vent, others are not.

The Range N up to and including the P140 / X140 do not have breathers fitted as standard. All other units are either supplied with breathers pre-fitted, or will be supplied with the unit to be fitted after oil fill. If the unit is to run at very high speeds, then we would suggest fitting a breather, please consult us if you intend to run a unit extremely fast.