The Hushy is a very good thing tough rare as. Mind you we have 4 or5 that race up here as solos but I think that might be Australias sum totla of them.
The pick in UK and cause of lots of angst, is the Rotax unit, 4 valves and light as fluck, and goes very well. Just read the Brit forums about 'em. They too put a stop to competitive big bangers making it to the tracks and with the flow-on rule they run with elec start et al...