On Negative, Positive, and Grounds

Dear Dr. Motorhead,
What a deal!. I can’t believe it. Spring came so early this year it defies the imagination. I was ready, I was pumped, I was going to be the first boat in the water. Nobody, not even Jeff Stebbins was going to beat me this year. I had the world by the tail, or at least I thought I did.

OK, the dock was in, lines were set, boat’s all clean, engine and garboard plugs in, and battery charged. I’ve read your stuff, I got it nailed. I’m ready to go. Only thing left to do is give her a quick dry-land start, just to make sure I am ready for the launching. This is great, the dog and kids were standing by waiting patiently on the dock, life jackets donned, anticipating my arrival while generating more enthusiasm than their old man. We were ready to be the Kings of Spring. Just one more minute while I give her a test start, I proclaimed.

Ignition on? On , I replied to myself as if I were Robert Redford in the movie, The Great Waldo Pepper. Contact I again shouted. With her arms crossed and shaking her head in disbelief, my wife suggests, “just start the thing, Waldo”.
Come on dear, this requires some drama , I proclaimed. It’s spring, it’s an annual right of passage. “Ah come on dad” the kids shouted, “get real.”

I knew then I was doomed; the Walter Mitty within me was squashed, unable to surface. Back to reality, I pushed the ignition button. The engine turned with such exuberance, it would have made you proud, Doc. I followed your advice: 12 volt conversion last fall. Guess what, turned over is all she did. Can’t believe it, my dreams, my hopes began melting before me as quickly as last winter’s ice. Don’t panic , I muttered to myself, what would Dr. Motorhead do, I queried. There is a solution, there always is, I hoped.

OK, gas, oxygen and spark…combustion, I remember. I’m alive and breathing, must have the oxygen. Next, gas. Absolutely full tank. Primed the fuel pump by hand with that little fuel pump thingy. Gas to the carb, could even smell it. Flooded? No, checked a spark plug – pretty dry. Aha, spark, the third crucial element to combustion. Check it out. Ground the big coil wire to the engine block, turn the engine over and see if we have spark. None, drat and double drat. Do I have power to the coil? Grabbed my test light, you betcha, I proclaimed like a true Min-ne-so-o-tan. Next, points closed, test light connected to Neg. and Pos. posts on coil. Bingo light there too. There is a complete circuit to the coil. What next, must be the coil…although, it was brand new last fall. Grabbed my spare, installed it, still no spark. Two in a row, unlikely. Test light in hand, check ignition wire to coil, perfect. Check Neg. post to Pos. post with test light, light on, perfect. Double check points, this time, I noticed they were open. How could that be, I am supposed to get a ground or completed circuit when they are closed and only when they are closed. I don’t get it.

My kids went fishing, the dog took a nap, my wife tended to the garden and I sat on the edge of the motor box wondering what Jack Dukes’ telephone number was. I thought I was pretty smart, I could figure this stuff out. I helped Bob Clark with his problems once. I attend all the BSLOL workshops. I have even been out to Lester Prairie Engine Rebuilders. Good guys, they taught me a lot.

Well, my anonymous friend, how can this be? How can you have a ground with an open circuit? Even with that, I have everything that is needed positive and negative to the coil why doesn’t the engine start anyway.
Bummed to the Max

Dear Max,
Go back to one of my first lessons. For the coil to send that great big high voltage to the spark plug there must be intermittent current to the coil. Points open and close. Spark turns on and off. Just like a doorbell, you have to let your finger off the button if you want it to ring more than once. Holding it down doesn’t work. I won’t get into the dynamics of how a coil works, just suffice, it has something to do with flux. Your coil provided one jolt of energy and that was it. In essence, your engines distributor didn’t take it’s finger off the button

Your points complete the circuit when they are closed or touching. The points are like a doorbell switch, they complete the circuit by grounding it. Open and close, complete the circuit then open it again, spark no spark. Remember, all this has to happen at the correct time, directing spark precisely to the correct cylinder at the right time.
Here is your problem. There is a little bolt that goes through your distributor near the top of the base. On the inside, it connects to your points. On the outside, it connects to the wire which leads to your coil. This is the grounding wire, the one marked with the (-) on the coil. This bolt must pass through the distributor case without touching any metal. If it does, the coil will be permanently grounded. Remember the doorbell, it will only ring once if you don’t take your finger off the button. Because you were getting a completed circuit with the points open, this bolt is most likely touching some part of the distributor, metal to metal. There are little fiber washers that prevent this touching or grounding. I am sure they have dried up or cracked. You need to replace them.
Remove the small nuts and wire from this bolt. You will notice metal washers and fiber ones. Stack everything in order as you remove them. On the inside remove the points spring from the bolt and pull the bolt to the inside. In addition, there should be a fiber bushing going around the small bolt. If not, you will need to replace this as well. Come to think of it, while you are replacing the washers, you might as well do it all right now. Your local hardware store has everything you need. I recommend going to Navarre True Value, as they are now offering free popcorn to their patrons. Get your popcorn first, very important, then proceed to the fiber washer section. Get two small washers, the same size as the old ones. The bushing is not going to be there. You will need to improvise. The cheap way is to wrap a small amount of electrical tape around the bolt. You can also purchase some of those electrical shrink tubes, these work pretty slick. Replace the bushing with whatever method you chose. Remember, you are attempting to keep the bolt from coming in contact with the distributor casing. Now, put it all back together in the same order it came apart. Actually, you need to put it back together in the opposite order. That’s it, you are ready to go.

If you have one of the small distributors on your Chris Craft, you may potentially have an additional problem. The points spring is very close to the distributor casing. There needs to be a spacer between the spring and the distributor. If this is missing or worn out, you will be grounding everything here as well. I sliced a piece of cardboard from a match cover and inserted it on mine about six years ago. Works just fine.

Piston wanted me to remind you that an electronic ignition eliminates this small bolt and any springs from grounding out the system. Just a thought.

Happy boating
Dr. Motorhead and Piston