For the guys having tuning issues, there are "traditional" needles made for the GO carbs. I belive 22racer files the stock LSN down on them too. See other brands of carbs you can go in larger incraments to tune them, GO's just need very small 1/2 hour turns to make a difference. It can be frustrating at 1st but when you get it right you wont have to touch it again. And if you do its due to weather, or moisture thats it. I went I belive 2 1/2 months last year without touching my carb. It was summer and hot. Just be patient. For the guy who got the Nova Limited if all fails and you cant get the GO carb tuned put the Nova carb on there thats the best part of that mill, and I am not sure wether you have the 3 5 or 7 port but all 3 race .21 Go mills will out perform that Nova. I am not knocking Nova at all they are awesome. And i hear our Go's are based off nova patents. That is a great little mill for $150 street price. The nova guys i know use them for buggy, on small tracks and the guys with deep pockets use them for practice. A little under powered for truggy unless modded.