Not much goes wrong with these. Jetting with the bing needs a bit of know how. You can use some Jap bikes clutch plates. New pistons etc on ebay. I would suggest fitting a PVL ignition. You can buy different pipes to move the power were you like it but standard is ok. Small MX tanks are hard to come by but not imposable. Forks unless there done need springs and and mods for best performance , You can retro fit yz forks and front wheel. DC does plastic kits and gazzi does a good shocks for this model.