RE: Saito shuts off
Warbird51 beat me to it!
As he says, try a new plug. I know you said it was a new plug already but even brand new items have faults on occasions (even Japanese products!) Anyhow - what do you have to lose!?!
Good luck, it'll be sweet as you like when you get it straightened out - you gotta love Saitos!
Cheers
Rick