Ok thanks all for the help I tried all of the above and all seems good Took filter off and butterfly opens all the way on full throttle and no brakes binding at all with or without throttle (engine off and rolling it) my mix was 200ml for 5l of fuel (MX5 synthetic motocross oil)
If I try and pull off with 1/4 throttle it hardly moves
I have put the carb back to factory settings and tired the car with the air filter off and no difference
I will ring rcmodelz when thay open if I can't get to the bottom of it
It feels like when I give full throttle on the remote the car only has half throttle but it all looks good hope this makes sense