A: The symptions you described lead me to believe your transformer may have a core that’s been damaged from overheating. Number 1033 transformers are very tough, but they aren’t indestructible. An abused core will seem normal under light loads, but as it warms up, the voltage will begin to drop since these transformers are unregulated.
It’s possible the circuit breaker just needs adjustment to correct the problem. A lot of bimetallic circuit breakers lose contact momentarily for short periods until they finally heat up enough to stay open. Your engine will slow down under these conditions because its powered with short bursts of current. Take the transformer to a qualified repair station and have the contacts cleaned and the breaker adjusted under the proper load. It isn’t possible to know for sure if your transformer is bad without testing it under controlled conditions.
