Please, I Need help tuning engine
 

I have a Nitro TC3 with a .15 Dynamite engine block but with a .16 megatech piston/sleve and head (I had a .16 megatech engine but the block broke when doing a gear change, so I used the Dynamite out of a ProBoat Miss Bud hydro I had) Since making the switch, my car runs like crap, I only had the chance to make a full run and it was idling way to low. I can't seem to get the engine tuned right at all, it keeps reving way to high and throttles by itself without me touching the triger...if I give the gas it stalls out, I keep messing around with the high end fuel mixture and the low end as well but can't get a setting on it...Could it be something to do with having a .16 piston and sleeve in a .15 engine block?... It's really frustrating and I'm about to give up on it, I have been trying to figure it out since early September.

any gap between the sleeve and crankcase can cause fuel and air to blow by the ports in the sleeve