That is a good point.

It cranks at full speed, like normal. Can't really smell gas,it's like it doesn't have spark. Thinking the computer is not letting it start. I thought I was doing good by putting 91 in it.

Still need a bit more info to clearly understand what is happening.
It starts when cold, go it

It doesn't start some times when warm.... Only after sitting after running and rafting up or other, or maybe just shut it down and 5 minutes later it won't start.

What happens between after the last time is started and this time it will not?

In the slip fires up, drive 10 miles at 4000 rpm up to wot. Get to beach let it cool down in no wake zone open the hatch. Hour later wouldn't start, checked everything cracked the fuel line at separator then it started. Next day fired up same went to the beach a couple hours later it started drove for a few miles stopped jumped in the water, then it wouldn't start got towed back to the beach. Went to go back home and it started. Thinking vapor lock?

Yes, sounds like VL
Can fix it by taking the return line and route it back to the tank (mines fixed this way). Otherwise take a rage and small screw driver or other. Remove cap off schrader valve, place rag over valve and press in on it. Turn key to ON a time or 2 until you get all gas come out

Yup many complaints of 52%EFI vapor lock issues over the years.
Try this for a search:
https://www.google.com/search?q=525E...hrome&ie=UTF-8

If that doesn't work, go to Google search or etc and type in: 525EFI Vapor Lock
and it will bring up many OSO threads

Awesome thanks I'll check it out.

I only run 87 octane Chevron pump gas in mine, in central TX, 100+ degree days. Ditto on the comment re 91. maybe start by lowering down to the reg unleaded. Merc Racing told me the 525 was built specifically to run on 87, and nothing more (needed).

I'd say if you are cracking the fuel sep filter open and it starts right after that, then its 99% for sure vapor lock.
87 octane non ethanol is the best fuel to run in them, but use whatever octane you have available that is non ethanol.