Oh yes…..the transformer leads reversed will absolutely do that. It’s good to remember that transformer lead colors can change, even from the same manufacturer, so use the schematic that comes with a transformer rather then relying on colors codes from the past.
Again, congrats on getting the Two Stroke up and running. BTW, my two red 2Stroke combos were used in a concert at the NAMM show tonight. They sounded great and got a fair amount of attention after the show.