My rider won't start it turns over fine and it has spark compression air and fuel getting to the carb but does not appeasr to be reaching the cylinders what could nbe wrong.

If you are sure fuel is getting to the carb venturi and you have spark, it could be flooded. Try cranking without a plug and then retry. Carefully shoot a little bit of starting fluid too. A lot of the time, fuel gets to the carb bowl but not the engine because the needle valve is stuck. Remove the fuel bowl, make sure the needle valve is free and the retry.

That and many tractors have a solenoid under the bowl that cuts the gas the moment the key is turned off. If the wire to the solenoid is bad or missing or the solenoid is bad the tractor will never start. Put your ear right at the bowl and turn the key, hear a click?