I don't know much about jet ski's per say, but a boats a boat. Look at the hull for cracks and chunks taken out of it, general condition. As for the engine I have no idea. The jet drive itself is simple enough, you would have to try to really hurt the impeller. I'd have a dealer go through the engine.

Be CAREFULL!!!!! People beat these things without mercy! I have seen them flipped, crashed, run without oil, sunk, burned, frozen, run out of water until the engine burned up, hmmm thats about it. For some reason people treat them like a disposable toy, or the owners are just clueless, or the owners are 12 and just don't give a crap.

I don't think I could bring myself to buy a used one unless I knew the owner.

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2006 CL500
2009 C300 4matic
1969 280SE
2023 Ram 1500
2007 Tiara 3200