98 mercruiser 5.7 no spark
 

Just put in a used 5.7 in a boat i bought over winter.i know its something stupid.no spark.i have a purple wire coming out of harness to + of coil 2 grays to - of coil wh/red wh/green to distrib. Im stumped

Carburetor with Tbolt V distributor or EFI ?

Are both the distributor and thunderbolt modules grounded? (they both have black ground wires)

Its carburated.i see 1 ground off of the bracket on back of distributor that holds the module? To big plugs that come out

Also i have constant 12 volt on both sides of coil

It is the mag distributor with the module and knock sensor mount right on distributor

http://www.boatfix.com/merc/Servmanl/16/16B4R2.PDF

Tbolt V starts on page 16.

Page 8 here show's complete wiring:
http://www.boatfix.com/merc/Techbk/96/96HGD4.PDF

Since it's pdf, you can increase size of page.Put curser to lower right of screen and you'll see - and + controls to increase/decrease view size.

That's not good. The gray's that go to - side of coil should not have 12 volts. One gray goes to tach (thru wiring harness) as signal and one goes to ign module so it see's rpm.

Remove gray that goes to tach and re check.

Ill try that today thanks