2003 Polaris MSX 140 Personal Watercraft Service Manual, Page 42Get this manual
Maintenance Hydrolock
A hydrolock condition can be caused by either water or fuel ingestionMost often, water ingestion causes hydrolock in watercraftA hydrolock occurs when water fills cylinder when the piston is moving downWhen the next piston fires, the piston with the cylinder full of water is forced back upwardSince water will not compress like air, the pressure is released in one or more of the following ways: Twisting crankshaft out of indexBreaking or bending the connecting rod andor piston pinCracking or breaking the cylinder andor cylinder head along with water outlet manifold and exhaust manifoldFlywheel key, starter motor damage