Mercruiser 470 Lost Spark

kyddvicous13

Seaman Apprentice
Joined
Oct 16, 2011
Messages
36
Hey everyone! We recently purchased our first boat from some friends. Its a 79 Chesapeake 212 with the 470 190hp engine. The boat had been sitting for a couple years, so I had the carb rebuilt, new plugs, changed oil, and changed coolant to start. I ran fresh fuel to her and it fired right up, and idled smooth. After about the third time I started I went to shift it into gear and it died. I am getting fuel but have lost spark. I have replaced the wires, coil, distributor cap, and even run a jumper wire from the bait straight to the coil to bypass anything from the key to the coil. The previous owner had installed a pertronix electronic ignition conversion in the boat which is the only thing I haven't replaced yet. I ordered a new one, but if that doesn't fix the no spark than I am out of ideas! I have voltage going to the distributor just no spark at the plugs... Any other ideas of what could be causing this?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,986
Re: Mercruiser 470 Lost Spark

After about the third time I started I went to shift it into gear and it died.

Ayuh,... Is the shift interupt switch centered in its groove,..??
Disconnect it, 'n try to start it....

If it starts, 'n the switch ain't centered,...
Ya need a New lower shift cable....
 

kyddvicous13

Seaman Apprentice
Joined
Oct 16, 2011
Messages
36
Re: Mercruiser 470 Lost Spark

I will check that. Wouldn't running power directly to the coil bypass any safety/switches though?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 470 Lost Spark

Also disconnect the tachometer, a shorted tach will kill the spark.
 

kyddvicous13

Seaman Apprentice
Joined
Oct 16, 2011
Messages
36
Re: Mercruiser 470 Lost Spark

OK thanks Don, that would prevent me from getting power to my distributor though wouldn't it? Sorry for the thousand questions im new to boats, and haven't had anyone's brain to pick! Where will this switch be located in relation to the engine? Im not sure if it still has the old style switch or the new plate.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 470 Lost Spark

Did you look at that link I posted in reply #4? The switch is on the shift cable bracket where the 2 shift cables connect. Should be on or near the engine.

If you study the information in that link, you will understand the system a bit better.
 
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