I can tell a 1 cyl 2-stroke engine has serious engine braking, 23cc in my rc car, it had air in the fuel lines due to a roll, ran up to 40kph, almost died out while at full throttle, slipper clutch failed so it blocked tires completely untill clutch let go.
Thats some serious braking power because even brakes cant do that to mine.
learnt me to let the car idle half a minute after jumps or a roll :P