Merc 200 problem missing bad above 1200 rpm

fredisdead

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My 1984 Mercury 200 V6 is not feeling good!

I have replaced the switch boxes on the engine and did an ohm test on the stator wiring found that the they are within spec. The boat had been sitting for a year. I added treatment to the fuel and it looks good, does not smell bad and doesn't have any water or floaters in it. Also drained the water seperator and it had no water in it.

I have checked the compression and all check out at around 130 within about 10 PSI of each other.

I also got a spark tester and verified that all the plugs are getting good spark and they check out. I have noticed that sometimes the spark is a little light then others however, would that have any significants?

So does anyone have an idea on what I should check for next. Its like the timing advance and retard are not functioning correctly. It feels like it is flooding out but when you back off on the power it runs ok again.

Help!!!

:confused:
 

Laddies

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Re: Merc 200 problem missing bad above 1200 rpm

Disconnect the 2 yellow wires from the rectifier and test run see if the problem goes away
 

fredisdead

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Re: Merc 200 problem missing bad above 1200 rpm

Thanks for your help.

What do the 2 yellow wires do?

I tested them with an ohm meter as the manual says and they test out ok.
 

Laddies

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Re: Merc 200 problem missing bad above 1200 rpm

Your not testing the yellow wires or alternator windings, your seeing if the rectifier is shorted
 

fredisdead

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Re: Merc 200 problem missing bad above 1200 rpm

Laddies:

So the stator is acting as an alternator sending to the rectifier to convert to DC and recharge the battery. Is that why the removing of the yellow leads will not affect the running of the engine?

Regards
Fredisidead
 

Laddies

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12,218
Re: Merc 200 problem missing bad above 1200 rpm

Yes, it also produces the AC current for the ADI ign. and if the rectifier is shorted it can cause the stator to heat and the ign. side to break down also
 

fredisdead

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Re: Merc 200 problem missing bad above 1200 rpm

Thanks that really helps me understand the interaction thats going on.

regards
 
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