Mine's on a GP 1/3 Pitts @ 15#, 20x10 prop, excellent starter and runner. My choice for any aerobatic airplane under 20#. Never needed a pump, broken in through one gallon fuel, burned only Morgan Mach 7 with 5%nitro, 50/50 castor/syn, cost me $11.00/gallon delivered ups 3 case quantities direct from Morgan, likes fuel but it burns less than a Saito 1.80 in my club; never needed big fuel line, I sold the airplane to a friend who insisted on running more expensive fuel plus added castor and the motor wouldn't run with 3/32 fuel line, but it's his money.I had the low speed disk move on me twice; must have been the o-ring creeping-strange...JIM