1987 6hp mercury

"I have an '87 6 hp mercur

"I have an '87 6 hp mercury that has a "miss" (top plug) at higher rpm, say 3/4 throttle or more. Gas is fresh, plugs are new (and made no change)
Could this be switch box related? This "miss" will clear for short periods and than return"

"Paul a "miss", if ign

"Paul a "miss", if ignition related on these little motors is more likely the trigger than the box and sometimes an intermittent problem is very difficult to track down.

The switch boxes on these are quite durable, but to be fair so is the rest of the ignition system.

The trigger can be tested for continuity as can the stator and coils (and I wouldn't rule out a bad coil or even a bad plug lead).

You do need to determine for sure that it is ignition - a timing light on each wire respectively will show you which one is missing and then you can trace it back from there..."

Spray some water around the wi

Spray some water around the wires and coil domes with a small squirt bottle while it is running. This may help determine coil or wire leakage.

"Thank you, I will have a clos

"Thank you, I will have a closer look this coming weekend."