hi,
MY sons quad is hard to start and seems to be loading up down low in the revs. This thing is stock other than removing the exhaust restrictor drilling out the air box {5 3\8 holes] bigger main [70] and leaving the 15 pilot in.I want to leave the auto lube on it , this thing gets used sometimes when i am at work so I know they would run it on straight gas and seize it up.
Any ideas ?

 

Going from the stock #60 main jet to a 70 is probably not enough added fuel to compensate for the better flowing air box. You may be able to tune the rough running out with the mixture screw on the carb but I doubt it. You'll probably have to go up another half size or two on the main to get it right or you might try blocking off half of the holes you drilled or both.