Mercruiser 140, no spark

jackball42

Petty Officer 3rd Class
Joined
Apr 2, 2011
Messages
76
Got the boat out today to get it ready for spring and went to start it but it won't fire. I checked the points and have a 1.5v drop across them when they are closed. I took a point file and cleaned the points but the voltage drop remained the same. According to the manual it should be .125v or less.

My question is, does this scenario make sense as to why I dont have spark?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 140, no spark

Put in a new set of points and condenser and give it a try. Once filed, they are junk, and if you have 1.5V of a drop, then they need replaced.
Points should be replaced yearly. Sitting over the winter is enough to kill them.
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,830
Re: Mercruiser 140, no spark

Yes it does. Try this: Remove the center wire from the cap and lay it next to a bare metal part of the block. Put a thin piece of insulating material between the points to keep them open. Ignition on, with a piece of insulated wire momentarily jumper across the points. You should get a nice spark from the coil wire every time you remove the wire. If you do, your points are bad.
 

jackball42

Petty Officer 3rd Class
Joined
Apr 2, 2011
Messages
76
Re: Mercruiser 140, no spark

Threw in a Sierra tune up kit (cap, rotor, points and condensor). It's alive again!!!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 140, no spark

Threw in a Sierra tune up kit (cap, rotor, points and condensor). It's alive again!!!

Well, there's a surprise! You need to make this an annual event, along with servicing the rest of the engine and drive system. Somebody on this board has a signature along the lines of ...

"When will people realize that (impellers/points/spark plugs/oil and fuel filters), need regular service and are not a 'drive it until it pukes item'."

You can put anything you like in there (...), the fact remains that the majority of mechanical failures have a root cause in 'lack of maintenance'....

Chris.........
 

jackball42

Petty Officer 3rd Class
Joined
Apr 2, 2011
Messages
76
Re: Mercruiser 140, no spark

The boat has not been started in several years. I have not had it running since I bought it last fall. I am restoring it. So, I will pat myself on the back for diagnosing and correcting the issue right away. All the other maintenance items have been done too.
 
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