I set timing as required and checked it many times. Set the valves, new carb and checked the fuel. Turns over great with great spark.
Question; is it possible that the spark timing is off? Can the cdi cause an advanced spark condition or something else? I also check the shear pin. I am lost? I thought I was good at this till this quad!

 

All internal combustion engines require 4 things to run. Fuel, Air, spark, and compression. If you have fuel, air, and spark then check compression.