1963 Evinrude Starflite iV 75 hp- No Spark?

[malarky]

Thank you F_R. I really appreciate your help! So if the coil is doing its job, the points are doing their job, the rotor its job then what do we have left? Seems to me timing or cap. The other idea is the points are doing their job, just not very well. In other words it creates a spark, just not enough to generate a spark at the plug?

BTW thank you Willy Clay for the manual links!

 

[Chris1956]

Do you have only a single condenser on that motor? A bad condenser would kill spark to all 4 cylinders.

Also, if the points on that motor are like my fat-fifty, they are connected together, and both need to be open to generate spark. In that sense, if one set of points was badly out of setting, it could affect spark to all.

 

[F_R]

Do you have only a single condenser on that motor? A bad condenser would kill spark to all 4 cylinders.

Also, if the points on that motor are like my fat-fifty, they are connected together, and both need to be open to generate spark. In that sense, if one set of points was badly out of setting, it could affect spark to all.

True, if they are way out of adjustment. Possible, I suppose.

 

[racerone]

Just a comment.----I am beginning to see posts where folks say that they can't understand carburetors or breaker points ignition.-----They have no issues with fuel injection or electronics-----How the world changes little by little.-

 

[malarky]

Chris1956- I am thinking condenser as possibility well. I have a new set of points I sourced locally and have a condenser coming by the end of the week. It has a single condenser and two sets of points.

Racerone- I am one of those that is more comfortable in a modern engine...but I really love this Evinrude and am becoming a quick study of '60's engine tech.

 

[racerone]

When you take the cowling off that 75 HP V-4 you can see / reach everything that might need attention.-----This 60's technology is simple / easily fixed / reliable.---Plus the motor will tell you it needs attention when it gets a little harder to start.------No sudden " what do we do now " type failures.------Just had some folks come over for a " power distribution panel " for an E-tec 150 HP motor.------New price is $900 CA+ tax for this part.----They were happy with a good used one.------No such big $ items on a simple 75 HP of the 1960's.----They use more fuel but an extra few coins for a weekend for fuel is OK.------A part that costs $900 might spoil your fishing trip.

 

[malarky]

OK- finally got spark to all four plugs by replacing the coil. In my coil research as I understand it, all 12v externally resisted coils are essentially the same- used in older cars, agriculture equipment and outboard motors. I picked up one at Autozone and verified that it is a 12v externally resisted coil. The reason I am asking this is when I check voltage at the coil with the key on and grounding to the engine, I am sitting at just shy of 6 volts (5.83) when cranking I am getting readings all over the place, but it showing anywhere from 9 volts and up to 13 and even 15. I am not sure if the shear speed of change during the cranking process is just to fast for my multimeter to make sense of. My biggest concern is pushing too much through and burning up the points. Another notable is the spark detecter I am using shows spark to all four cylinders, but 1 and 3 are brighter than 2 and 4...does that indicate I need to check point gaps?
The coil that I removed was a prestolite unit which I assume was original equipment.

 

[F_R]

I think you fixed it. Voltages sound good. I really wouldn't be concerned about the differences in brightness, but double-check the points gap if it will help you feel better.

Just FYI without getting into a bunch of electrical theory, when the points are closed there is a current flow through the external resistor and the coil's primary winding. That current flow results in a voltage drop across the resistor and coil primary, the amount of voltage drop across each depending on the resistance of the two units. Adding the two voltage drops together will equal the source (battery) voltage. When both sets of points are open, continuity breaks and therefor current no longer flows, so there are no voltage drops .and voltage returns to source voltage around 12V more or less. Yes, your meter is being confused when the voltage change so rapidly.

OK, I know I've already lost most of the average bears reading this. But it's just basic electricity 101. A lot of bears might benefit by a bit of study on 101.

 

[malarky]

Thanks. I was assuming (hoping) issues with the meter might account for the high readings. To your point, if I am going to run this motor, this is great 101 info to know for the future. I'll tell you to that I spent less than $50 dollars on rotor, points, condenser and coil. While the coil turned out to be the culprit, the points were worn/black and I am sure the condenser was aging as well. Now short of wires and cap, I have renewed my ignition system. I am planning to pick up an extra set of points and a condenser to keep in my onboard tool box, just in case.

 

[Willyclay]

When F_R posts in a thread, I pay attention because I usually learn something.

F_R never fails me!