1994 85 hp loses power

[moondog049]

Hi, l I've got a gremlin in my 94 85hp outboard, it starts fine and runs well but after an hour or so it loses power and drops to a high idle and will continue to run at low speed until I turn the engine off and then restart it. It starts right up and runs fine for another hour or so until it happens again.
My dealer thinks a coil is shorting out, I've checked them and they are within specs but an intermittent problem could show normal.
The top 2 plugs are dark and don't seem to have as hot of spark as the bottom one.
Does any one have any other ideas?? thanks
moondog049

[boats.net]

Use a timing light to check to see if cylinders are firing when rpm's drop.

[99yam40]

Might also check to see if the timing is advancing properly while problem is there and you have the timing light hooked up. Safe mode retards timing to limit RPM

[moondog049]

Thank you for your advice, I'll try one and let you know...