Lost some rpms going from saber to the xp oil so the xp must not be as thick as saber ? From 13 k dropped to 12400 piss reving ,pulled the muffler cover after 4 tanks ,looked less sooty with xp ,put a new plug in and it is pretty white after 4 tanks ,is starting to get some color on one side though,i did retune to 13 k ,will check again after all fuel gone from can ,seems like i lost some grunt around 6_7 k in the pass ,it may have been my chain though ,it only took about 1/16 of a turn to retune