well boys we upgraded or 23 cc standard redcat engine and put a Darksoul cylinder head on and change piston and went racing this weekend/ today and we ran rich on half tank of fuel a nd striped main clutch gear off the clutch drive but on the happy not it flys we just need our metal gears to stand up to the treatment as for the darksoul head yep great improvement and gets up and goes cant wait to start leaning it out stand by for that moment