I’d remove the injectors and put in a couple of ounces of Marvel Mystery
oil or
transmission fluid in each cylinder and then next day turn it over with rags on the injector holes to catch the oil spray, turn it over for 30sec or so to make sure oil is getting everywhere and reinstall injectors and start up.
Might want to wrap a rag around each
fuel line as some will spurt out unless fuel shut off is engaged.
The oil is likely unnecessary but goes into the can help, can’t hurt and is easy to do category, turning it over without compression is the same, may help, can’t hurt.
Do NOT replace the injectors without spinning the engine and letting the oil blow out, or you could hydrolock it and hurt something
My
boat motor was 27 yrs old and had 500 hours on it when I bought it, think just maybe there were long stretches when it wasn’t run? Probably more than one.
Since then I have put another 800 or so on it and it seems fine, burns no oil and cranks easily etc.