You haven't given us a lot of details so it's rather hard to understand the situation and give meaningful advice... []

However; this is the beginners forum so I can make some assumptions...

When a engine "Cuts out at Full Throttle." , the usual culprit is the pilot that tuned the engine too lean. [&o]

A new pilot usually has a new engine that is not properly broken in, and the pilot is too green to know what that means.

So what you have probably done is tuned the engine for the highest possible RPM and then went flying.

Once in the air the engine "UNLOADED" (with the AC in motion the engine had less resistance and went even faster!), now the engine is going TOO FAST [X(] and the oil in the fuel is not keeping the engine cool enough so the metal on metal of the engine over heats, expands and then siezes (binds) which means that the engine stops and you now have a glider... [:@]

The Solution; tune the engine for 1-2,000 rpm less than max, allow the engine to break in for 1- 2- gallons of fuel and then retune for a higher performance.

This is a common fault and solution for newbies.