The Yamaha uses a gear drive oil injection that has been on their snowmobiles since the 70s. The Evinrude is a stronger overall runner but I think the Yamaha is a slightly better motor because of the oil injection.
Yamahas oil injection is heads and tails above OMCs Vro system. Is the the VRO even hooked up on the Evinrude? Vro is not a bad system but requires more Maint.