1981 Johnson 115hp will start and run, then after stopping will not restart.

Help!! Its driving me crazy! I own a 1981 Johnson 115 HP. I've had an ongoing problem this season. The engine starts and runs well. I turn the engine off and it will start up again right away, but if left off for awhile It will not restart. The next day it starts.

I have cleaned the fuel tank and the pickup screen in the tank, rebuilt the carbs. I even replaced the stbd ignition coils; there was a fraying wire inside the wire covering.

I replaced the starter with an after market starter?? I have been reading, when the engine gets turned off, and thus stops cooling, the starter picks up the ambient heat, causing the starter to get weaker??? Not sure if there is any truth to this or not?

It will crank but it just doesn’t catch.

Any ideas? Solutions preferred!

It's possible that the starter is picking up too much heat. An after market starter is around 60 bucks, so a simple replacement might be the easiest option. As you probably know, those motors have to be cranking at 350 rpm before they will energize the system.
Have you looked at your stator? They also can get overheated when the motor shuts down.

Test to see if you have spark when it wont start...sound like stator or timer base problem if no spark

Observe the Stator under the flywheel closely. If it is dripping something sticky looking... replace it. A stator in that condition would probably function close to normal when cold, but when hot would fail completely.

It takes time to get to things, thank you for those giving me avenues to check. Recently I pulled the flywheel and visually inspected the stator. It looked like it was new. It’s not, but there was no rust, no oozing black substance. It looked clean.
After approximately 20 minutes of rest (off), the engine will not restart until the whole engine has cooled down. I purchased a volt meter. How do I test the stator with the meter? How do I test the starter when this condition occurs.
NO there is no spark on any of the plugs when this condition occurs.
More input is appreciated. Thank you.

Opinions vary.----I would start with examining your OLD starter.----Take it apart for inspection and test ohms from commutator to the shaft.----Should read infinity.-----I install new brushes at $6.00 a set.----Costs very little coins and you also learn a lot.

When hot, is the engine cranking over as fast as it did when cold? The starter must crank the engine over at least 300 rpm in order for the stator to energize the powerpack. A slow cranking engine will result in weak, erratic, or no ignition/spark.

Did you examine the bottom of the stator? ... visible via a good flashlight... no need to remove it for inspection.

The ohm reading between the "Brown" & Brown/Yellow" wire of the stator should show a resistance reading. I'm not sure of what it should be... somewhere around 600 ohms I think. What is your reading? Between either wire and ground should be zero.

When this "no spark" problem pops up, does removing the black & yellow striped wire from the ignition switch cause the spark to return?

I completely removed the stator, so I could give it a thorough visual inspection. There was no sticky substance any where on stator or on any adjoining parts.

I did not think to check the rpm of the flywheel during the problematic condition. Thinking on it, it is erratic. It does act different between cold and hot start. ll have to confirm that.

Just take the starter apart.----Inspect it .-----Have your battery load tested at an automotive shop / garage.----Inspect your battery cables.----Perhaps look at another solenoid too.----All simple to do !!

I did an ohms resistance test on the stator ( charge coil). I got a reading of 530. According to the repair manual it should fall between 485- 635 ohms. Ok....so my stator is good. So I’m back to wondering about the new after market starter?

I also made another observation. Prior to changing ignition coils on the stbd side, I had no tach. With the new ignition coils the tach is showing indications of life. The indicator needle moves but bounces. The bouncing IS NOT indicative of the actual rpms. I would hear and feel that kind of fluctuation in the engine. The bouncing must be more a symptom of electrical. I’m now wondering about the port side ignition coils??