Seized/flywheel issues?

A buddy of mine got a boat and a little 6 horse Evinrude from the mid 70s not exactly sure what year exactly but I’ve been trying to get the motor ready for him and it was sitting for 4 years without being used so I figured it would be seized so we put transmission oil in the pistons and let it soak for a day and then I took a breaker bar and tried freeing the pistons but nothing was budging so then I opened up the lower end and everything looked good no metal shavings and everything looked fine. I’m not sure what to do next. The flywheel will turn each direction to a certain point and will stop and not budge. The shifter works fine. when it’s in neutral the propeller spins freely and when it’s in forward or reverse the same thing happens I can turn it both directions and at a certain point it stops and when I spin the propeller it spins the flywheel. I don’t know if I just have to soak it longer with oil and try freeing the pistons again or what. Any help or suggestions would be great.

I would remove the cylinder head and have a look at the cylinders.----All of the ignition coils have failed on these motors.------If they are still original then plastic pieces under the flywheel might interfere with flywheel.---Should be easy to figure out what is wrong.---I have about 10 of these motors and can rebuild one without a glance at a manual.

Just how far can you turn the flywheel before it stops and won't budge? If more than a tiny amount, the pistons are not stuck. Actually, it depends on their position in the cylinders. It will turn more if at top/bottom dead center. As a quick alternative to pulling the head, you might try sticking a screwdriver into the spark plug holes to see if the pistons move any at all when you turn the flywheel as far as it will go.

Diagnosis is the key before tearing stuff apart.

Yeah I took the head off so I could see the pistons yesterday and they move the top one will come all the way out and the bottom will go all the way in and they both get stuck in the middle of the cylinder so the flywheel moves at least half way around

And they are original

Two guesses.

1.Something loose under the flywheel
2. Something in the ceankcase, like a loose connecting rod cap screw.

Your mileage may vary.

I bought one a few years ago that was stuck.-----Got it moving and turning.-----Then took it apart for inspection.----I remember putting a wrench on these things at the shop / dealer years ago to loosen up a stuck motor.-----Could ask the owner and if they said it was sitting in the garage for 5 years we would start it up.-------Back then there were only a few motors that were 20 years old.--------Different today as many 50 / 60 year old motors are out there.

Ok thanks for the help I’ll take the flywheel off and take a look underneath