The parents in law gave me a jet boat, it hasn't been started in 5 years. The boat resided in NH on a trailer on their yard for 5 years, so it has seen freezing temperatures frequently. From what I understand, 6 years ago the boat ran fine at the end of the season it was winterize. At the beginning of the following season, the owner was unable to start it and just gave up.
It is specifically a 1991 or 1992 Boston Whaler Rage.
The manual can be found here: Boston Whaler Rage Manual.
The boat has a Yamaha two stroke engine in it ( model number : j650c ).
The engine has been submerged in water up to the drive train. When I went to change the spark plugs and found that one of them was loose. There was about 3oz of water out of the chamber under the spark plug that I sucked out. I tried moving the driveshaft with my hands but I am unable.
My next plans are to spray 'PB Blaster' in the spark plug holes, probably a couple times over the course of a week, and then use a wrench to try and get the driveshaft spinning.
Is this a reasonable thing to do?
Is there anything else I should lube to try and get the driveshaft spinning?
Should I be more concerned with other aspects of the boat?
The driveshaft should be able to move by hand, correct?
I understand the impeller may be frozen as well, should I detach that from the engine before trying to spin the driveshaft?
These motors want the oil mixed right into the gasoline for the engine, is there any other place where I should be changing oil?
Any tips or advice will be much appreciated!