Hello Bill Just took out of box new .61 went to bench run it with 11-7 prop, high speed 3 turns out, throttle 1/3 open runs maybe 15 seconds burns out head gasket. is this a common problem or did I get a bad gasket? All bolts and screws were pre checked for tightness. Thanks

We don't know how a 15-second engine run at 1/3 throttle could possibly burn out a head gasket. We've seen engines run at high throttle settings for longer times with warped heads leak through the cylinder/head junction and still not "burn out" a head gasket.

We'd need to see the engine to see what any potential difficulty may be.

HUH !! I will have new gasket set for it friday. If it does it again I will use it for an anchor for one of my float planes, Faster way to solve the problem than shipping it .