The are both very early builds, mine the first delivered to Albuquerque.

Guys, guys,
You're all putting your finger in the air in the hope you can detect the direction in which the wind is blowing.
Not good as you all know, if you want to determine accurately the direction in which the wind is blowing you need a weathervane or a wind direction sensing measuring device.
All of the responses to this post are reminiscent of the wind direction scenario above.
Just how long is a piece of string, there needs to be accurate and determined diagnosis of this issue before we get any where near to a solution of the cause. Stabbing continually in the dark will lead to endless paths to nowhere, excessive cost through diagnosis by substitution not to mention the terrible amount of time wasted.
Start with the basics, look at the handbook, first point to note is that they inform you after riding for one hour let the machine cool down for while before the next hour of riding.
If this unavoidable i.e. you must ride in excess of 4 hours, then one must rethink or modify the cooling system to cope with riding for this amount of time. Consider high mount radiators, larger volume radiators, more fans or higher volume fans, changing the sensors for the fan to allow them to kick in sooner and run for longer. Give your machine a chance to survive the rigours you are putting it through, it is after all just a machine, and like all machines has limitations to which we take or push it to.

GMSAHFR

Hi all again,
So how are you getting on with this RLemon5.
Without my workshop and diagnostic tools to determine precisely what you may or may not have wrong with your ride, there are few obvious pointers to note as follows: -
•   Major good point to note is that there are no warning signs, warning lights or excessive indicators with oil pressure or water temp. (Excellent indicators)
•   It starts perfectly with none of the above warnings after you have left it for a while. (Another excellent indicator)
So, my first question would be is there any problems with this ride, working blindly it would appear that there is not.
Ok fine, so the 64-dollar question is, why does it not start after a 4-hour ride. Back to my previous post on this one i.e. "Just How long is a piece of String".
To correctly diagnose this issue, one would need a diagnostic tool plugged in during the non-start situation, not your average amazon purchase "P" code reader but a proper Automotive or CFMOTO diagnostic tool that reads each EFI sensor including ECU parameters with all 12-volt feeds being displayed.
However, I fully appreciate that this is Eutopia in so far diagnostics are concerned and not everyone has access to this level of diagnostics.
So, what are the potential scenarios given the information I have that RLemon5 describes: -
•   After a 4-hour ride despite there being no high temp warnings when the ride is switched off there is incredible excessive heat build-up, with nowhere for is to dissipate to with total lack of air flow." They pump cold air into the radiators of F1 cars when the pull into the pits for this reason i.e. to dissipate the heat build-up" Therefore, when you attempt to restart the EFI ECU is protecting the engine i.e. it's too hot. The Engine temp sensor has reached the level of its high temp parameter and prevents the start; I could prove this If I was there with my diagnostic tool and seeing no power to the fuel pump. Alternatively, if the EFI ECU has not done this and is actually pumping fuel for whatever reason, it's so hot inside the combustion chamber fuel is evaporating and not being ignited. This kind of makes sense under these start conditions because the EFI sensing high engine temp will cut back and reduce fuel delivery from the injectors, so the minute amount of fuel therefore evaporates under the extreme hot conditions.  To prove this theory in the field we pump a CO2 cold gas fire extinguisher around the combustion chambers.
•   As per my previous post on this one, if 4-hour rides are necessity perhaps re-think the length of time for ride. Major modifications to the colling system is required as described in the previous post. This of course is the first consideration of all those ATV and UTV racers conduct to their rides before the start to race i.e. major mods to the cooling system. It doesn't stop there but there is just not enough room to describe what else they do in this post, maybe another day with another challenge.

GMSAHFR