Pair Valve

[Kompact]

Has anyone blocked those off and removed the pair valve?

[easyrider]

I do not know why you would do this.If you removing the cat and replacing the exhaust yes you can but you would have to block it off,if you leave it open you will get backfire which is sometimes desirable if you are on a Harley and you want to have a pop pop on deceleration.Biker boys like that,but not necessary for a scooter engine and would end up being counter productive.You are not going to get any significant gains in doing so and you have to change out your entire exhaust system.The pair valve regulates O2 in the exhaust stream in order to stoke the platinum in the cat so it burns off harmful emissions.