30% runs hotter, make sure you have plenty of air exit area keep it rich too. I went from a 12.25 x 3.75 APC to a 14 x 4 on my 72 on the 30% and it still revs higher. Maybe I will try the UCD in the snow? The sonic can stay together in the car though, no field assembly helps keep the fingers warm, nothing to do with starting. My Saitos will start by priming them really wet (until you hear it slosh) the just flip the SPINNER cone backwards against compression and off they go, no stick no starter, nice shiny TruTurn spinner. Messy muffler? Maybe if I had the time, maybe the 30% will take it off. it eats everything, be careful!

Mac