I recently got a 250 trxr its all rebuilt all tricked out and the guy told me it takes a 32:1 oil mix but the bike itself says 20:1 oil mix. Does the upgrades of the bike make a difference in oil ratios?  

32:1 ratio is a great mixture.  20:1 is almost to much oil. I would use the 32:1.  

I've run 32:1 in everything from stock machines all the way to my fully built Banshee and never had any problems. Just make sure you always use the same pre-mix all the time. if you switch to a different oil and put it in the tank with the previous pre-mix it could cause problems.  

what pre mix are you using