The design of the Enya head is interesting being bore of the insert in the head that holds the contra is the same as the cylinder bore the contra easily transverses
both unlike the the Davis and factory Irvine heads using a smaller contra that does not project into the cylinder, so is really a contra in the cylinder like many of the classics such as PAW. This also eliminates the stuck in cylinder bore we see in the classics sometimes. For a 10size engine (11 of course) it quite a bit heavier than the OS and TT 10s. The twin needle carb that Fiery describes might be a good upgrade, might be a little on the pricy side?? martin