actually i dont think thats a rod bearing, but more of your piston rings, or you overheated your engine and the cylinders expanded/warped. But prob rings.
My thought is if it is having trouble starting when its hot(which usually is the opposite where it starts better hot) then your losing pressure past the rings, meaning when its hot, the cylinder expands, thus making the gap bigger and losing even more pressure. When its cold, the cylinder walls are not expanded and therefore tighter and able to hold pressure. get a flashlight and look in the spark plug holes to see if theres major scoring in there or if there is any black/ aka oil escaping tot he top of the cylinder and burning. has your machine been burning oil at all? Also get one of those cheap compression testers and check your compression, see if its good, and make sure!!! that both cylinders are about the same pressure! and that they both are firing. a missfire can also cause these symptoms.
I am no engine mechanic but thats my deduction.
Now as far as it cutting out... could be related to the problem above, but it does nto seem as likely..
I would say it is most likely the fuel pressure. NOW it may not be the pump, check the fuel filter to make sure its not plugged, and/or just take off all the fuel lines and blow em out to make sure nothing s stuck in them. Use and air compressor or something. Not sure how to check fuel pressure on atv's... i know how to on cars? lol
On lets say... weed wackers, and small engines, when I have that same problem it usually is the carburetor or the fuel line, carburetor is plugged up or whatever..
I know the atv is efi, but check your injectors, to make sure they are not plugged as well, if you have a tuner on your quad where you can check A/F ratio that would be good too, just to make sure your spot on, you could take it to the dealer and have em plug in to the ecm also for that.
lets seee...... what else... oh rod bearings..! uhh when the engines running do you hear clunking/knocking? not from the cvt, but from the engine? if yoy dont then the bearings are fine.
hers a vid of what bad bearings look like
heres one of the actual sound
those are EXTREME cases... but hey, its shows what to look for with out a shadow of a doubt.
Hope if not that!!!! if it is replace them NOWWWWWW do not run the machine any longer and cause more damage, cracking open rotax engines is easy, if your a little mechanically inclined, just write everything down and take lots of video for reference when putting back together.
Hope this helps!, please also listen to other opinions because I am no engine mechanic, but I am good at tracking problems.
Good luck Dude!