This does work. It has an effect on the engine though. If your going to do this do it as stated. Do not remove the valve all together. Leave the spring in place. Just cut off the small Vacuume port like it says.
Doing it any other way makes it run RICH.!!!!! Fowled my plugs and made it had to start removing the whole valve. JUST DISABLE IT if your going to try it.
The purpose of the valve is to stop the bike from back firing when you go from half to full throttle to idle. It uses the vacuume of the engine to open the valve and put more gas in the system allowing it to be burned in the cylendar and not the exhaust pipes.
I do Not advise disabling the valve since I have found by trial that it also helps in acceleration due to the higher vacuume created. The Bike I tried it on did accept it but only after adjustments were made to the idle jet. It took a few tries to get it right and it did create a backfire in the exhaust system once the engine was at operating temp.
I put my bake back the way it was designed to be operated.