i have a 1979 merc 40 hp with thunderbolt ignition. the moter would only run half throtle one night while out catfishing. it had been having trouble which seemed to be the carb so i rebuilt it and that didn't crue the prob. yell in the mean time the fuel pump went out so i rebuilt it looking into it further i found that the coil for the top cylinder was corroded, cleaned it out with sandpaper and took it to the lake for a test run with the same results. i got 2 new coils but the marine store gave me one right and one wrong so the other is on order should be in friday or monday. meanwhile i put the right new coil and the old coil that seemed to be firing good on and tryed once again, same results! it runs good hooked to the ears in the driveway better than i have ever heard it run goes in gear fine and revs up like it is ready but once you get it in the water and warm it up with the throtle try to put it in gear it boggs down and dies. any advice would be awesome since i am running out of options. i read somethine about it could be the reed valves and i bought two new ones but would like to hear a little more before i get into taking the intake off
thanks
Chris
thanks
Chris