Problem w/engine it is not the slipper
 

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.

Problem w/engine it is not the slipper
 

I am not familiar with that truck, but make sure there isnt any slipper type clutches slipping on it.

Not slipper
 

It is not the slipper it is super tight. Is the clutch pad in the middle just before the gear supposed to be flat. Now the car does not even move, the engine goes but car just sits there.

Problem w/engine it is not the slipper
 

Do you have a local hobby shop that can inspect it? Sometimes its easier to look it over than guess on the net here, did you do anything different with the clutch in the swap process? something has to be different, maybe the clutch is plain shot?

Problem w/engine it is not the slipper
 

Could be the diff, if it has balls. Or it could be the flywheel...

Problem w/engine it is not the slipper
 

Thanks guys I think that is what I will do take it to my LHS and have them inspect it for me, thanks for the help.

Problem w/engine it is not the slipper
 

My guess is the clutch is worn out. When you put in that powerful engine and nailed the gas, the pads didn't have the grip to get a good hold on the clutch bell and you probably melted them trying to get it going.

Also, have you glued on your tires? If you have check them to make sure they are still glued. If you get just a tiny bit of water into the bead of an unglued tire it will slip forever.