Originally Posted by j8ight13

hey guys do you know if i have to remove any shims in a untuned grp .21? I just got one at a great price NIB and the engine bearing already went!! i was told not to use nitrotane. So i did and after a gallon...rear bearing went.

Well i want to run 20% like i always have, but just want to make sure my head clearance it good. Thanks guys!!