Sorry for the delay, That mixer is ok but the CA300-50 series would flow more air. I assume this is spliced into the air tubes coming from the factory airbox? If so you need to make sure all of the connections on the engine side of the mixer are tight, if you leak air there it would cause the issues you are having. If you could post some pic's of the system it would help. The mixer could also be sticking the "piston" (air valve) in the center needs to move smoothly as airflow into the engine is what makes it work, If it is sticky it could also cause you issue.
hi thanks for info so far trying to learn to post pics i cut intake tubes off for 300 a at 20 " from intake took model e apart every thing moves free tried different model e same thing doesnt run at lower rpm dont see no air leaks