Hot Spark--- Weak Spark---Hot Spark--- Weak Spark

[Don Smith]

Johnson V-4, 85hp 1976. I have a Hot Spark, Weak Spark problem. Sometimes the spark is so hot it jumps 1-1/2" to ground. <br />And then without changing anything, the spark goes weak. The big problem is it seems the weak spark <br />come at the worst time. It usually hapens just before I stand up and wave my arms for a tow in. The motor can be running <br />when the spark goes weak, but keeps running till you shut it off. Then it will not start with the weak spark condition. <br />I have replaced, Coils, Powerpack, Stator, Rectifier, Flywheel Key and Ignition Switch. I even disconnected the Engine Stop Wire from both ends (black/yellow). <br />When the spark is hot, it starts with just a bump of the starter, looks like less than one turn. Compression is #1-137 #2-140 #3-136 #4-140. Ran out of things to check or replace. <br />It has this problem in or out of the water. Motor is on a Bayliner Trophy Fish and Ski 17'.. <br /> Please help me find this problem.

 

[ICEMAN]

Re: Hot Spark--- Weak Spark---Hot Spark--- Weak Spark

Hi, DId you replace the parts with new parts or used parts? Try indexing the flywheel, what you do is, remove the spark plugs from all cylinders. find the top dead center of each cylinder #1 is cast in the flywheel. Put a mark on the flywheel adjacent to the timing pointer and mark which cylinder it is. Use "White out" to make a line on the flywheel. you should have a line about every 90 degrees. put the spark plugs back in and hook a timing light up. run the motor and check the timing on each cylinder. you should see only that cylinder near the timing pointer. if you see two cylinders, when the light flashes, you may have a double firing power pack. Let us know.

 

[Don Smith]

Re: Hot Spark--- Weak Spark---Hot Spark--- Weak Spark

I put on a used one off a good motor first, then I bought a new one. Both powerpacks and the original all 3 do exactly the same thing. I will do the "each cylinder" timing check and get back with you. Thanks a bunch.

 

[Don Smith]

Re: Hot Spark--- Weak Spark---Hot Spark--- Weak Spark

Oh yes, and the rectifier was new also.

 

[Don Smith]

Re: Hot Spark--- Weak Spark---Hot Spark--- Weak Spark

My Son admitted to hooking batteries up backward. Have posted other findings