Re: what to look for?
I posted this on a similar post, and I think it works here as well.
DO NOT buy a boat without an on the water test.
The big reason, is problems can be covered up with paint and new oils.
A test run will tell you more about the boat than anything else.
Before the test run, check the engine oil level and color (make a note) do the same with the drive. The 92 should have a dipstick in the top. Just be sure you take some new gaskets with your for the dipstick. (NEVER reuse a gasket on the drain, vent, or dipstick plugs. You do not want to see milky oil at all.
Then do a test run, at idle when the engine is warming up, listen to the engine. Any odd noises, growling, knocking, clicking, etc.
Turn the steering, any grinding or knocking noises or changes in the sounds back there?
Where is the temp gauge when warmed up, make a note, oil pressure, make a note.
Take it for a run, allow the owner to drive. Have him get on plane normally, and trim the boat out and you keep an eye on the gauges, especially the temp. With a raw water cooled engine, it should never exceed 170? or 175?.
Go to WOT rpm and trimmed out. What is the rpm. Should not be below specs for that engine.
(specs are 4200-4600 for a 3.0L and 4400-4800 for the 3.0LX models)
If it is low, that means they have been lugging the engine, which is very hard on an engine. If over 4 or 500 rpm below specs. There are problems, and and may take a while to figure out why, and probably NOT the prop when that far below specs.
Also look at the temp gauge after running at WOT for 20 to 30 seconds. Then back off to cruise speed and watch the gauges.
This whole time you should have been listening for any weird noises.
Head on back and park the boat.
Shut off engine. and after getting boat secured. Do another oil check. Look at the level and the color. Is it milky and over full? If so, you probably have a cracked block. Many times cracked blocks don't show up on muffs, just not enough water from the hose to make it leak.
Once on the trailer, check the gear lube again. Milky means water. Another new gasket.
Boat back on trailer, pull drain plug. Did the boat take on water while running? if so................ WHY ???
You should now have some idea the shape of the engine and drive.
One note. I don't know about other sellers, but I would never allow a buyer to do a compression test or any work on the engine or drive. I don't want someone I don't even know taking things apart on my boat.
If you want a compression test and a drive pull to check the ujoints, bellow, etc. then you need a certified shop to do the job, and YOU pay for it. Not the seller, it's your inspection.