Need help. My 1978 Mercury model 700 3 cyl. 70hp. starts up and runs good when first put in the water but after shutting it down to fish for awhile it starts again but very low power when put in gear. Last season it was running great till all of a sudden one day it just quit. I replaced fuel pump, fuel lines, new floats, new needle and seat valves, new fuel tank, cleaned carbs, new plugs, new water pump. Spark check shows all 3 spark jumping 3/4” gap. Compression check showed 145, 143 and 137. A mechanic looked at it and put on a supposedly good but used trigger and spark pack. It ran good at first but after shutting down for a bit and trying again it does the same thing...hard to start up and real low power when put in gear? I’ve read others having similar problems with this motor. Anybody have the cure? Thanks.
