2010 rzr 800 bogging

Hey everyone, I have been dealing with this problem for awhile now trying to resolve it and thus far my attempt have been useless , my 2010 polaris rzr will start and idle fine but 10 – 15 minutes into the ride I will trying giving it some gas and the engine will just bog out on me be giving me no power no rpm.
I am still able to drive at very low speeds just to get myselg home .
Where did it all start. Well I took it out and had punted the Rad while riding and i was about 3-4 hrs in the bush , so I had to crawl it back trying not to overheat it too bad but ofcourse it did and damage was done.
Since then we repaired everything we could fine, it seemed to run fine and then this issue started with the bogging , so we went back changed the fuel pump , took a part the engine noticed a couple valves were leaking fixed that , new pistons and the works , cleaned the t-bap sensor and still all of this did nothing to help resolve the issues I did take it in and all the mechanics at the time said was it’s probably the valves and so this is my last request for possible help before I end up spending way too much to repair it .
So if anyone had any suggestions my ears are open. Thanks