A few options. If the AB 33 or 34 mag, the trip finger will be a different shape and length. if a rotary mag, type R or J, the gear will be a different diameter than the one on the 2 HP. If san ignitor engine, unknown by me
Watersedge - A couple of words of advice as I have a FMZ 6hp and am currently working through the same challenge. The FMZ's used the AB 33/34 until 1926-ish and then switched to the R and eventually the J rotary mags. If your crank/gov gear is helical cut (gears cut at an angle), I would strongly suggest you install the AB 33/34 flipper mag as finding the helical mag impulse gear is (almost) impossible; I gave up after a year of looking and built one. If your crank/gov gears are straight-cut, the choice is yours; the 35 tooth straight-cut impulse gears are around, as are reasonably priced FMJ mags and impulse couplers.