Home › Forum › Ask A Member › 1936 Johnson A-80 4.5 hp power head HELP! › Re: 1936 Johnson A-80 4.5 hp power head HELP!
On the crankshaft the center area is the rotary valve, there are 2 compression rings that fit into slots in the block and compress against the crankshaft. These are the only thing that could hold it up, maybe if one of the rings got out of its slot it could catch on the intake ports in the crank, or one could be broken also catching on a port. Other than that you have the top bearing out or just unbolted and there is nothing on the bottom. Should just slide up.
The disc under the exhaust is as you guessed an exhaust relief for starting. It’s open at the correct starting position of the throttle and timer, then closed as you accelerate.
Right again, the accordion baffles are listed as anti backfire in the parts catalog.
Good luck getting the crank out, mine was the opposite, the rings were stuck loose so it came out to easy. I was able to clean the grooves out and they should be fine. I hope this helps figure it out.