What oil
#3
It depends on the final drive, if your quad uses an internal centriugal clutch to run the front drive clutch, it will still need wet clutch compatible motorcycle/atv oil. If it spins the front clutch directly from the output shaft, then it probably can use automotive grade oil, it will most likely have a seperate transmission area that will need a different oil. Last I heard, Hondas had a cent. clutch set up, so 10-40 car oil might not be the best thing to run, it may not say "energy conserving" which means slippery additives that will cause clutch problems, but car oils are just not set up to run in the internals of a quad, too many shearing forces compared to a car motor.