I just installed O.S. .12 cv-r into my rush used my old clutch set up from my Ofna force .12 engine. I put 5 tanks idle in my engine then drove it around at slow speed for the next 2 tanks the Rush. Then the next tank I gradually started to add more throttle and it still goes slow, I am not to sure if the clutch is not engaging, at one moment It was going real fast then started to slow again. The engine RPMs real high but car truck does not go that fast. I lift the tires off the ground it goes really fast put on groung goes slow. Any help would be aprriciated. How does the clutch set up supposed to go, I am pretty sure I put it on correctly.