1994 Merc 200xri firing issues

[jstrehl]

Took my Ranger out for the first time since December. Boat would not get on plane, would only turn 3000 rpm at the most. Checked plugs on the water and plugs were not fouled. Took the boat to the shop and had mechanic start diagnosing the problem. Compression was 122-125 on all six cylinders. Stator checked good, trigger checked good, ignition coil voltage checked good. Checked the spark on all cylinders and only a few would jump a 7/16" gap on the spark tester (mechanic says strong spark should jump this gap). One switchbox checked good, the other the voltage would not stay up on the high side. Replaced both switchboxes with brand new Mercury boxes. Took boat out, and it only runs 39 mph, 3700ish rpm. Get it back home, hook up spark gap tester, only #6 cylinder will jump a 7/16 gap. Swapped #4 coil wire to #6 coil and #6 coil wire to #4 coil. neither cylinder would fire. swapped them back to their respective coils, no fire. Check continuity of wire going from switchbox to ignition coil and showed no resistance. I am at a loss as what to do next. Does anyone have any ideas of a direction to head next?

 

[bmcnatt]

Did you ever find a solution to your problem? This is exactly what is happening to us.