Used wave runner purchase

[GeauxDeep]

Hi guys, my brother in law and i have been talking about buying a couple of used wave runners. Found out he has a friend who is looking to sell both of his on a double trailer. I have been looking online for skis for months now and done a fair amount of research about buying used. I just figured i'd post on here to get a little advice from some more experienced people and make sure I'm not forgetting anything. I have a 2015 AR210 that i bought new so i'm pretty familiar with things just wanna cover everything. His friend is selling a 2017 Yamaha EX Deluxe and a 2005 Yamaha FX Cruiser High Output on a dual trailer, located in the Virginia Beach area. Should find out hours for both and asking price some time later today. Some of the things i'm going to ask/inspect are:
-What was your flushing routine/how often did you do it (since he lives in VA Beach i'm certain it was used in salt/brackish water, ideally he flushed it everytime but we'll see i guess) I know how to run my boat on the hose so if he can walk me through his process without me leading him then that would be a huge plus in my opinion.
-oil condition/level/color
-last oil change
-spark plug condition, when were they changed last
-overall condition of the engine compartment
-hull condition, look closely for any gelcoat/fiberglass repairs
-steering smoothness
I also want to start them and warm them up, obviously on the water if i can and ride them. after they're warmed up i want to do a compression test. I have never done one before but i've been reading up on it. Does the compression test kit have to be for a specific engine or can i just get a generic kit from harbor freight and use that? Would anyone be willing to give a basic rundown on how to do the compression test? Also for the trailer i'll check lights, condition of the bunks, bearings, bow straps and winches and tires. He has the titles for all 3. What else am i forgetting to look at or ask him about for the skis or the trailer? The saltwater is what makes me the most nervous. He can say he flushed them every single time and i guess theres no real way of me knowing for sure. All pointers or advice would be gladly appreciated.

 

[Gunner]

I had a 2017 EX deluxe. It was a nice machine for the one season I had it (sold when I bought a boat). Top speed when solo was about 50mph. This model is on the smaller size with not alot of storage. Its nimble and fun but not as comfortable as the bigger machines. Since I was in brackish waters and salt I flushed everytime with Salt Away. If I bought another one it would be a bigger machine with a better ride (BUT IM OLD)

 

[Gunner]

One other thing is get under machine and check the condition of the impeller thru the intake grate. Small dings and wear are normal, big chunks missing are not.