Carryall 300 won't turn over.

[pogrelis97]

Trying to get my mother in laws carryall 300 running for her, she bought it from her parents who moved into a nursing home 6 or so months ago.
I went to pick it up for her last week and it would try to turn over but wouldn't start or turn over more than 1/4 turn. I brought it home and it was way full on oil, I'm pretty sure it was gas in the oil making it over full. so I changed the oil and pulled the spark plug and it turns over great. put spark plug back in and it fires right up. once you take your foot off the pedal and let the motor stop it won't turn over again until you pull the spark plug and can start this whole process over again.
It seems as if its getting hydro locked, has the Subaru ex40 motor. anybody experience this issue?

[Fairtax4me]

Never heard of that on the Subaru motor.
Common on the older carbed motors.

When you pull the plug out and turn the motor over does gas spray out of the cylinder?
Those motors are very high compression and have to have the correct starter belt, and have to have a strong battery. Is the battery old? Is the belt old?

[pogrelis97]

Pretty sure its the battery not being quite strong enough, if it's hooked to the charger it starts but if you unplug the charger it won't quite turn it over.