With this much info, its going to be hard to diagnose... Replace all 3 spark plugs with the correct "surface gap" ones. Make sure the battery is FULLY charged! Check the rotor button and the cap for signs of shorting..(dark streaks or smudges inside the cap). The rotor button and the cap condition are CRITICAL!
Test the compression...is oil sufficient to coat cylinderwalls. Make sure float level is correct n no vacuum leaks. Battery must always read 12.6v for acoil ign..noless. Buy a repairbook online forthat bike ...dont stray
Bad design of the trike. There should be no driveshaft movement between the engine and final drive that would allow it to move off the splines. Guessing it is something to do with excessive suspension movement.