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Re: Modern Yanmar Diesel Sat for 3-4 years
"Any" internal combustion engine that has 'sat' for several years and that wasnt 'prepared' for long term storage, should be verified that the piston rings have not become frozen / stuck / rusted BEFORE attempting to start such an engine.
Simple procedure: remove injectors / spark plugs (or open the compression release on a diesel if it has one) and attempt to HAND TURN the engine ..... with large 'breaker bar' and socket attached to the crankshaft nose bolt. Gently, attempt to rotate the crankshaft; if it turns 'easily' then good, start the engine. If there is a lot of resistance to hand turning, then spritz in penetrating oil into the combustion chamber to free-up the piston rings in their grooves, let soak; then try to wiggle (do not use force) the rings loose. Keep soaking, etc. until you can 'wiggle' the rings free and ultimately be able to easily hand turn the engine over. For severely rusted/frozen piston rings, sometimes it can take a week or more of 'soaking', rocking/wiggling to free up frozen/rusted piston rings.
If you dont do this check, etc. or FORCE the engine to turn over with the starter, etc. you are at risk for breaking the piston rings.
Last edited by RichH; 11-28-2015 at 10:06 AM.