I just recently bought new R21 and I am really liking the performance so far with almost a gallon thru it (30% ODSPBlend plus 2% Bryons Lube Booster). But I am not sure when and if I should remove shim that manual says to remove after break-in. I did use the heat cycle and the motor is really coming around and running first real race this weekend and I will leave the shim in for this race so I don't have to tune it again right now. Should I pull it once I pass the 1 gallon mark or wait until it's had 2 gallons thru it? Also should I add a percent or two of lube booster (castor oil) after break-in is finished to my fuel if I can only get Odonnell Speed Blend 30%/7.5% oil content? One more thing I have noticed a VERY small amount of fuel coming out behind flywheel from front bearing this is normal as long as it's not alot and will hold tune right? I know I ask alot of questions and THANKS for all the info/help that I have recieved here!