sounds like all your mechanic did was reverse the plug wires. you can swap them back to where they were if you pop the dizzy cap, mark EXACTLY where the rotor is pointing, then pull the dizz. drop the oil pump (it's messy), rotate the gear 180*, and put it back in using one bolt. put the dizzy back on (180 out) and see how much you need to correct it. once you get it so that it lines up with the mark you made, bolt everything back together and you're good to go.