I have twin 150 Yamaha 2 strokes and have been trolling with them going on the 6th. season, never a problem, use synthetic oil,and change plugs every other season,other than the spring jig, I mainly troll.
As far as fuel burn, 2 gal. a day with kicker vs. 8 gal without , This is on a boat that weighs 6500# before passengers. BIG DEAL!!