View Full Version : Weak Spark

05-27-2014, 11:39 AM
'85 S&S, Pleasurecraft 351. First attempt to start this spring, the engine turns over but will not fire. Gas has StaBil added in the fall and I can see gas in the carb. Tried starting fluid anyway but still not firing. Was planning on a tune-up so went ahead changing plugs, points, condenser, cap and rotor. Still would not fire. Put timing light on first cylinder and cranked and got no indication of voltage going to plug.

Took to marine dealer to have them look at it. Started right up for them. Ran fine and restarted several times for them. Put it in the water and it ran fine with several restarts during the day. That night I wanted to make sure points and timing were set properly so checked the points. Tried to start and again, it would not fire. Checked all connections between points and condenser. Made sure nothing was grounding out. After two rounds of this, it finally started again. Next day, again no spark and it would not fire even after several checks of the points, condenser, etc.

Pulled coil wire from distributor and checked spark by holding it close to ground while cranking. I did get spark but only when practically touching coil wire to ground. Even then, barely visible. Hooked up a new coil and tried again. It gave one strong spark then started acting just like the old coil, small and weak spark.

The next day it started right up but died after a minute and would not restart.

To summarize, the problem is intermittent but now almost constant. Getting fuel. Problem occurs with old and new points, condenser, cap, rotor, coil.

I'm going to remove and clean ground wires. Tried to check ballast resistor but my meter is not working. Any suggestions?

Thanks for any help,

07-13-2016, 09:24 AM
Did you ever get a resolution to this? I see you didn't get any responses.