1971 Mercury 500 thunderbolt powerpack help needed.

Janek1982

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Jun 9, 2013
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2
engine serial begins with 285***** and the part I need to fix or replace is 333-3213.

symptoms i had were. Idles and starts well but wount get rpms higher, misfire sputter at higher rpm. Sparkplugs are wet as hell.
We did hook up timinglight and noticed at idle the spark and timing is perfect but as soon increase rpm it will cut out spark for a 0.5sec as we raise rpm it will increase the cutout time. Did ignition driver coil test and the specs are fine.

Well i opened the powerpack up and kinda started to hate all the epoxy and small stones in the unit. i couldnt save the ceramic condencers and some tupe of glass diodes (were there for safety purposes i think). can someone guide me through this repair or has a diagram to build working one for this engine? got some 1N4007 diodes and a 3uF 630VDC/400V capacitor. old capacitor discharged way too fast.

Any help is appreciated. Sorry my english is not so good so no comments about grammar.
 

Janek1982

Recruit
Joined
Jun 9, 2013
Messages
2
Re: 1971 Mercury 500 thunderbolt powerpack help needed.

That s/n actually comes up as:

50 1970 Short & Long 2736807 - 3008818 2742142

From here:

MERCURY OUTBOARD MODEL YEAR GUIDE 40 HP (4-CYL) - 50 HP -- Mastertech Marine

Parts listing for model 1500100:

MERC 500-7/8 - Mercury, Mercruiser, Force, etc. Parts Lookup

See item 1 under STARTER MOTOR, STARTER SOLENOID, RECTIFIER AND WIRING HARNESS

Gerry

Well its 266 euros and i could get working merc 500 with 350 euros so new part is out of option.
So has any tried to repair it or has diagram and components list?
 

schematic

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Jan 12, 2008
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1,102
Re: 1971 Mercury 500 thunderbolt powerpack help needed.

ain't gonna happen....
 
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