WARNING: Always set your boat up so you can kill the engine with the radio. You will need a kill switch connected and activiated by a 3 rd channel to kill your engine reliably. Simply closing the carburetor will NOT kill the engine reliably, you MUST have a 3 rd channel kill switch installed. Some radios have a feature that allow you to mix the 3 rd channel with your throttle channel, this will allow you to engage the kill switch through your throttle trigger. Read your radio programming instructions and understand them. DO NOT operate your boat until you are positive you can kill the engine reliably with a kill switch of some type. You need to contact the kill switch manufacturer/supplier and get the correct kill switch that is compatible to your particular radio. For example, you can review the gas kill switch atwww.killerrc.com A good kill switch will also be a fail safe if you have radio issues. Shop for quality, not a cheap price.