2012 polaris rush 800 mid range stall then takes off

[Rush it]

I'm new to this forum but I have a 2012 800 rush just put a new spi head pipe on now it has a mid range stall then takes off anybody have any ideas what might be

 

[Jorgy]

Is your check engine light on? My pro was doing that and I had a code for the egt sensor. After I got the code to go away it fixed its self after riding for 15min. I think bad fuel was an issue too I had poor fuel with the premium resistor.

 

[Rush it]

Have you heard of anyone running this without controller

 

[gedakbx]

I would assume the head and pipe added some power did you change the clutching at all

 

[knocksum]

Heavier clutch weights are needed.