Just had that happen to mine this past summer. Please check for the magnet on your drain plug. The upper one came out of mine and went through the gears and wrecked the whole drive. I am in the process of overhauling mine because of that. I should have said upper plug, not lower.
I had another thought on this, if the spark plug seat was machined a little too deep in the cylinder head, it would cause the plug to extend too far into the combustion chamber. Could do a measurement to compare to the other plugs at the top (plug wire end) to see if it's the same.
I just googled images of the motor. I don't see a bolt in any of the photos so don't take my word for gospel. It may just be pressed on but that's a new one to me!
I've never see one without a bolt in it. Without the bolt, you are relying on the keyway to take the load which could cause serious issues. A puller will get it off, but be sure to clean the threads in the crank and get a bolt in there. Just my 2 cents.
Dude, pull off the cathode and "rubber plug", install the block off plate and gasket with bolts. DONE. No sealer unless the mounting surface is corroded then YES, sealer.
I just went through this very same issue and posted about it. My boat blew a line off inside the boat and I figured out it was the manifold. I replaced the manifold and purchased a replacement anode assembly as well. The OEM mercruiser part included the seal. The manifold I purchased had a...
Not to beat this to death, but.....if the tape is applied to the crank pulley it will show degrees BTDC to the right of the zero line on the pulley, If the thing had a pointer on the timing cover with degree marks on it they would show BTDC to the LEFT of the zero mark if it is a standard...
