hello everyone. come across a bayliner with a mercury 850 with the thunderbolt ign, from 1985 i think. engine runs great on the hose, but when taken out today for the first time the engine dies when you put it in gear.compression is 120 0n all cylinders. got to go a ways on the lake at about 30 mph. got back to the dock, let off the throttle and the engine died.engine would start back up ,but when put in gear again it would die. also would like to know how many turns out the mixture screw should be. dont know if timing might be off or what.when i got home i ran it on the hose and ran fine. also while out in the water i could manually open the carbs and would rev fine until put into gear again. any help would be greatly appreciated. thanks