Alot of the screws are extremely tight, and the allen heads are sometimes not punched too good making it easy to strip the screw out. The ones you really need to watch are in the center "spider diff". If you strip one they are very hard to find. 2.5x22 mm. Other than that you can do a mod to the front upper arms to get more caster adjustment, but I still like mine with the stock setup for most conditions. Another thing is the motor. Before break in its also really tight, and hard for the included starterbox to turn over. Just preheat the motor with a blow dryer. Have fun:hi: