'96 Mercury 150 EFI
Ser.# 0G406555
Took my boat out Sunday for the first time since mid-summer, it fire right up but when I started to accelerate to get on plane it bogged really bad. When I shifted to neutral it cut off. After that it was hard to start and I would have to throttle up in neutral to get it going just to get back to the ramp. Got home and discovered with an in-line spark detector that #1 and #4 cylinders had no spark. After researching this problem I tried switching the coils and sure enough the problem moved with the coils. Is it common for the coils to go bad just sitting up? I know that it is recommended to change all six coils and I plan to do so. I see OEM coils are around $55 and some Sierra aftermarket coils can be had for $30 or so.
Does anyone recommend staying away from aftermarket ignition parts? I replaced both of my power packs 2 years ago with CDI packs and they have served me well so far. Also, I've been running NGK BU8H no gap plugs in this motor for many years - is this the correct plug or is there a better option?
Thanks for any and all responses.