Rolling ATV - GIF

[PJs]

Frank is right about the duration of being upside down. I think that is a Yamaha 350¿ I used to ride the 250 version and when I endo'd it the motor was still running on top of me upside down. I've also seen them running after steep hill climbs and tumbled backward down hill till they stopped then having to shut them off upside down or on their sides. Most quads also have an internal oil pump to force oil to the overhead valve train located low to mid height in the crankcase. So Overall the duration probably isn't an issue, IMHO.

As for Carbs Hemmjo mentioned they are available but not on standard quads. Standards are CV (Constant Velocity) which has a vacuum diaphragm at the top to help lift the needle. The other is a Slide type using a cable to lift the needle or similar to the old SU types that have a vacuum and cable to rotate the butterfly.
Here is a link to most common....https://barebonesmc.com/motorcycle-c...omplete-guide/

Honestly I think the bigger issue is structural integrity on the front suspension and frame components over time.