Premix ratio

Hi, i recently just started with the jetski life. My friend had a 97 waveblaster 2 that he rarely used as he had 2 other. we got it back up and running this summer and just took it out today. We werent sure on the pre mix ratio to use as we converted it to premix. we had it at about 75:1 today as the bottle said high proformance is 80:1. but after reading some posts i feel that is way too high and should lower as i have heard 31:1 all the way up to 60:1. does anybody have any suggestion, or specifics for the Yamaha Waveblaster II? Thanks for all your advice.