Airplane: 72-inch low-wing Telemaster, 6.5lbs.
Motor: AXi 2826/12
ESC: Exceend 80A, OPTO
Six volt receiver battery.
Battery: Flight Power 3 cells, 3350mAh, 30C.
Prop: 12X6 APC
Test performed with Astro Watt Meter.

In flight the motor cuts out. Go to low throttle, then full, and it comes back. But cuts out again. Lucky! Saved the airplane.

Bench testing with the Watt meter shows voltage as being OK, fresh charge above 12V. However, amps are only about 18. To get more amps, obviously I need a larger prop. But that does not explain--at least not to me--why the motor should cut in and out. I understand that the ESC will cut the motor if the volts fall below LVC. But that is not the case here.

Is it possible that the low amp draw (needing larger prop) could cause the same problem.

I have considered the possibility of a bad connection, but if that were the problem the motor would not respond when going to low throttle and back to high.

What say yee all?

--------------------------------------------------------------------------------

I would think you may have over propped slightly.

Try changing your timing and see what happens. it's a fairly common complaint.

I hardly think I'm over propped with a 12X6. Actually I'm under-propped. Please read my original post.
Now:
Consider this possibility:
One: Not enough amps (25) just enough amps to get the plane airborn.
Two: Once airborn, the volts drop causing the amps to drop even further.
Three: So, maybe the motor never did not actually quit. Maybe it just seemed to quit due to the sudden lack of sufficient amps.
Does this sound plausible?

The above proved to be the case.

Now you know--should anybody ask--25 watts per pound will get a 72-inch low-wing Telemaster off the ground. It just wont keep flying.

According to the AXI data a 12x8 on 4s would draw about 32A (well within the 37A max rating)...that should give you plenty of get-up-and-go!

Right Dr. Kiwi!
On 25 watts per lb, the airplane climbed out to 30 feet before losing power. Went to low throttle, then back to high regaining just enough power to maneuver for a safe landing. By the way, this is a LOW WING Telemaster (named Funster V2 from Hobby Lobby). I'm sure glad it is such an easy flyer. Otherwise, I would never have made it back alive.
Now, I'm not going to embarrasses myself any further by explaining why I was attempting to fly this airplane so under powered. I am switching to 4 cells and 13X7 prop.