Need advice about ignition system on a 1973 evinrude 25

[Lukeaulgur]

Hey all, first post. I use this site all the time... I have a 1973 evinrude 25, model 25302 a. And I have a parts motor that I believe is a 75, model 25502b.
Anyways, I can't get it to run right at high speed under a load. Runs great in a barrel, will rap out and blow all the water out of the barrel but when you put it under a load it will only go maybe 2500 rpm.. It feels like a 10hp
I'm pretty sure its not a fuel problem. First I bought a new fuel line, fuel tank (yes it is venting) and didn't fix the problem.
Then I swapped the fuel pump from the parts motor didn't fix the problem
Then I swapped carb and replaced all fuel lines and same problem..
Primer ball stays firm while running.

Now for ignition.. Of course I've swapped coils got new spark plugs bought 1 coil off ebay and nothing changed.
Then I pulled the flywheel and swapped everything. Points, condensers, the driver coil (what does the driver coil do?) even swapped the flywheel.. I don't know a whole lot about ignition systems.. I have a cheap volt meter but don't really know how to test coils or points.
So it is possible I just did something wrong and I understand that these parts from this parts motor may not necessarily be good, but for the problem to stay the same after everything is very frustrating. I have a manual and have been doing it by the book
Also compression is 120 and 118
And it pisses water good
I'm just out of ideas, I've. Been cleaning ground wires I just don't know how to narrow down the problem. Any advice would be greatly appreciated.
Thanks
Lucas

 

[hardwater fisherman]

Make sure the points are clean and gaped to .020.

 

[oldboat1]

compression sounds good. Pull off plug boots, one at a time while running. See if you get a change.

 

[Lukeaulgur]

I will re check the points, and if you touch the spark plug wire or boot while running it shocks the hell out of you. Is that normal?

 

[Lukeaulgur]

And I can't remember what the manual said to clean points with.. I used electrical contact cleaner, think that's ok?
And thanks, by the way

 

[Scott Danforth]

you file points. I use a points file

then you regap the points

however your problem sounds like fuel related.

when was the last time you pulled the carb apart and cleaned it.

 

[Lukeaulgur]

I haven't pulled the carb apart.. I just swapped carbs with the parts motor and the problem didn't change.. I had myself convinced that it wasn't a fuel problem because while driving across the lake when its bogging down, I sprayed mix gas from a spray bottle in the carb and it bogs even more.. Is that a good test? It made since to me Lol but I could be wrong

 

[F_R]

I don't see any mention that you have checked the spark---a real test other than getting shocked. So, does it have a strong spark on both cylinders, yes or no? You may not have an ignition problem at all. Other things can cause it to run on one cylinder and lack power. For instance, a busted reed (leaf) valve. Or water ingestion into a cylinder. Or too little (or too much) gas.

But if you indeed do have an ignition problem, the most common cause on that motor is breaker points. Your manual won't tell you what to file them with. In fact, it will tell you not to file them. Yeah, I know, we all do--including me. But it's results that count. If you don't do a good job at it, the problem will only be worse.

With all the parts swapping you've done, you have muddled the situation. We just can't predict what may have happened. Only guess.

 

[Lukeaulgur]

Yes I forgot to mention both plugs appear to have good spark with all these coils I've been swapping. And I was saying that it shocks me because oldboat1 said to pull off spark plug boot while its running and see if there is a change...
With 4 strokes I have identified fuel problems by spraying either in the carb and see if it goes or bogs.
Is that not a good test on a 2 stroke Because reeds maybe?
I will order a point file and try that. Won't be able to test it until this weekend but I have plenty of time to tinker with it and I'm open to any ideas/advice

 

[Lukeaulgur]

I don't see any mention that you have checked the spark---a real test other than getting shocked. So, does it have a strong spark on both cylinders, yes or no? You may not have an ignition problem at all. Other things can cause it to run on one cylinder and lack power. For instance, a busted reed (leaf) valve. Or water ingestion into a cylinder. Or too little (or too much) gas.

But if you indeed do have an ignition problem, the most common cause on that motor is breaker points. Your manual won't tell you what to file them with. In fact, it will tell you not to file them. Yeah, I know, we all do--including me. But it's results that count. If you don't do a good job at it, the problem will only be worse.

With all the parts swapping you've done, you have muddled the situation. We just can't predict what may have happened. Only guess.

And I don't see how I muddled the situation with all the parts swapping? I did things one at a time and went and tested it. I do understand that the parts I'm swapping may not be good also..
And could that be symptoms of bad reed valves?

 

[F_R]

No offense intended with the "muddled" comment. I have no idea what your experience or skills are. But lots of people keep taking stuff apart and make it worse. You may not be one of those guys. Sorry

 

[Lukeaulgur]

No offense taken F_R. I took the points to a buddy and he filed them for me, he said they were a little pitted. But I gaped them to .020 and have my fingers crossed. Going to go test it tonight or tomorrow. I'll give an update.
But does anybody know if that is bad if I get shocked if I touch spark plug boot or wire while it's running? Everybody I have asked said its fine as long as its not shorting out to anything.
And what does the driver coil do?

 

[hardwater fisherman]

I have a manual for a 40hp with the same type of ignition. It is too much to type out. As 1 set of magnets passes the driver coil the current goes from one side of the driver coil through one set of points that are closed, and then through the mag plate to the other set of points. Which are also closed, And then back to the other side of the driver coil. When the point is open the current enters the condenser and then to the external ignition coil, which steps up the voltage and fires the cylinders. Keep in mind this is just me giving a summary and not the actual functioning of this system. I do know that if the driver coil goes bad you will lose spark on both cylinders. So if you have spark on one then it is probably not the driver coil.

 

[oldboat1]

Try running the motor at night and look for arcing around the boots, wires or grounds. There's always a risk of getting a jolt, but yours sounds a little excessive.

Need leather work gloves or pliers with plastic grips (or both) -- but should still try pulling off the boots one at a time. When you do that, you should get an rpm change or stalling. If you get no change, chances are that plug isn't firing.

It doesn't sound like you are using a spark tester -- need an adjustable, open air tester (auto parts store, maybe $10 or so.) Look for around 1/2 inch bright spark.