Quote Originally Posted by "G" View Post
Possibles
Loose conection
dirty connection
wire too small
fishing line wound up behind prop

and Yes....you need to have a circuit breaker or a fuse size will be determined by what TM you have.
I would add my comments along as "G" posted.
Remove the prop to check for possible line or plant residue behind the prop.
Sounds like the prop shaft is bound an requiring extra current to operate.