Anybody good with merc's?
 

we just recently put our v20 in the water. it has an 1985 merk 200hp v6. at 1st it ran great but then it would slowly rpm down and die then it would be a bi*ch to start back up. when we got it out of the water i tested to see if all the cylinders had spark. oddly all the plugs on the port side sparked perfectly, all 3 on starboard had no spark at all. I'm thinking maybe control box? im really lost when it comes to boat engines so im hopeing someone can help me out! thanks

Ferm, Bigshrimpn, or Spare will be along shortly to have you fixed up.

I will give it a shot in their absence.....DO NOT LISTEN TO ME!!!!

Could be the power pack for that bank of cylinders or it could be the reverse cut out switch that someone else had trouble with recently.

Or something else that I don't know about.....wait for the experts to answer.

Sounds like a switch box gone bad to me. The easy way to diagnose would be to swap switchboxes from one side the the other and see if the problem moves with it. Ferm or Shrimp will be along shortly with a more detailed answer.

i would agree switch box you have two of them one for the left side plugs and one for the right side its easy to replace could also be the stator but sounds like switch box to me

Knock on wood, my MERC has been trouble free. If I had to guess I would say switch box though. Common problem for the MERCS to lose em. RAPAIR/CDI is regarded as being the better replacement for the switchboxes.

thanks guys for the quick response. i didn't know the switch boxes were interchangeable.. that will definitely be my saturday morning project, switching them around. i'll keep you guys posted. thanks again!

bad news guys i just switched both boxes around and i'm still getting no spark on the starboard. so now i eliminated the idea of a bad switch box what should be next on my trouble shooting?

if its not the switch box check the stator,im not sure how to do that but im sure someby will tell you

yep sounds like one side of the stator is out, you can ohm out the stator but i always thought that test sucked. best test to do is to DVA the stator but you need a special meter or an adaptor from cdi elec to do that. or you can ghetto dva the engine like you did just you dont get any cool numbers to look at. before you drop 300+ on a stator check the grounds and if they are good then thats most likely what it is.

is it hard to somehow remove the stator and take a look at it? i seen them on the internet for about 150$... if it isn't the stator or bad grounds what could it be.