I agree, I put a KX100 engine, ignition system and pipe in my son's KX85 chassis, and it is a woods weapon!DougRoost said:I prefer the KX100 (or a RM100 if you can find one), especially for woods. Less peak HP than the 85 but more torque. Add a flywheel weight, handguards, and skidplate and it's a woods weapon, with a 6 speed that gives it scary fast speed on top.