1982 Mercury 50HP Thunderbolt Ignition

matthewch88

Recruit
Joined
Sep 27, 2009
Messages
4
My 50HP is about to give me grey hairs. When I first got the boat, it would run down the lake then get hot and go to idle speed and wouldn't rev up. So I had the carbs cleaned to no success. Then it quit firing on two cylinders so I changed the power pack, fixed my firing but not my first problem. I then also changed the water pump and found bits of old impeller vanes (the top of the block reached 197 degrees). Still no fix to my problem. I finally pulled the powerhead off and cleaned all the water ports and passages (removing 4 more impeller vanes). Still no fix but my max temp on the block is now 143 degrees at the crank just behind the carbs. Then I did some research to my voltage coming from the stator and going to the power pack then to the coils, keep in mind that I have equal spark on all cylinders. I got my reading with the motor cold, which was 2.75 volts to each coil at idle. Then we ran it down the lake and it began acting up so I checked my volts. I had 1.2 volts to each coil now at idle with 85 volts from the stator. We also found the rectifier housing had bubbled where it had been so hot previously. We changed the rectifier and all four spark plugs. I keep looking for a stator, but can't find a stator like mine. My flywheel has glued on magnets and my stator is coated, 4 wire and 9 amp with a part # 398-5454A21. The only thing they make now is an uncoated stator which is not operational with my flywheel. Does anyone know where else I can look and does it sound like I've trouble shot the engine correctly? Is there anything else I need to trouble shoot?
 
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