Just got a free 1990 cajun with a 1989 johnson gt 150 put it in the water and runs good but makes a clicking sound when running. I can turn the flywheel by hand and it makes a low accrordion sound. I think the piston rings are burnt up and letting air blow by. I have not done a compression test yet. S o should i be able to turn it by hand or do i need to take it to get new rings put in? How much dose something like that cost?