problems with a mercury 25hp

Hi guys, i recently bought a 25hp mercury and is meant to be a 1995 model but i cant seem to work out what year it is by the charts on other websites, the serial number is 9541211, would appreciate if someone could help
Also i took it out on the lake last weekend and it runs really rough, vibrates the hell out of the boat and is cutting out when its at full revs! ive checked spark, and both cylinders are getting fuel but had a slight 'miss' every now and then at idle. and can hear it more as i accelarate. does anyone know what can cause this?

cheers wayne

Bad coil on one cylinder is my best guess. Buy a new coil and swap it out on the top, then bottom. One of them may be the culprit. It's unlikely that BOTH are bad, but I've seen a slew of bad coils lately.


Jeff

PS: Those gapless plugs are hard to read. If you put a set of Champion J6Cs or Autolite 303s in there and run it at WOT for ten minutes, the dirtier plug will tell you if it's a bad coil, and which one. You can then confirm it by switching the wiring (primary and secondary) of the coils and see if the problem follows.