4.3 cutout switch diagram needed

dwayne80

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Joined
Apr 24, 2011
Messages
9
Having problems with my 1990 4.3 lx mercruiser alpha 1, getting no spark, timing is on, coil good, figuring I got a couple wires mixed up somewhere. If someone knows where to get a cutout switch diagram, and the exact wiring diagram for the engine, got one off here earlier that was similar but not exact. Serial number is OC775123, Thunderbolt IV ignition, thx for any help.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: 4.3 cutout switch diagram needed

getting no spark, timing is on, coil good,

If you don't have any spark, how do you know the timing is good? The engine has to be running to check the timing ??????
If you have no spark, follow the flow chart below to locate the problem.
All you have to do is disconnect one of the wires to the shift interrup switch to see if that's what is causing your no spark condition.
Here is a link to the Service manual, it has the wiring diagrams http://www.4shared.com/document/1FdjddET/Service_Manual_07.html

TB4troubleshooting.png
 

dwayne80

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Joined
Apr 24, 2011
Messages
9
Re: 4.3 cutout switch diagram needed

Topped #1 piston, lined up arrow under dist cap to 1, close enough to fire. Cutout switch wires were somewhat mixed up, fired now
 
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