Wanted to put these facts in it's own message (not trying to pop the thread up).
I talked to BV Powersports themselves on the TrailMaster 300 XRX. Hopefully someone searching like I was will find this useful as many sites have misleading or confusing information:
Engine Oil: 15W30 is best, 10W40 is usable but not as good. This unit ships with "shipping oil" and you are expected to immediately change the engine oil upon receiving a new unit.
Gearbox Oil: MoS2&W-2WD-4D means 80w90 and it has a single gearbox (reverse is in the same box). They have oil shipped in it but recommend changing it immediately incase any dirt/debris are in there from manufacturing. Here is a couple pages BVP sent me on engine and gearbox bolt locations:
http://ertp.com/docs/TrailMaster_300...t_location.pdf. NOTE: This unit often ships with NO gearbox oil!
Max Capacity: 500LB (this can be in one seat or spread out between 2 seats and rack, it's all fine, just do not exceed 500LB)
Hope this helps someone!