ya know I thought it was a good idea at one time to tell i tried it that is . to touchy and sucked up some of the colored water in to the carbs . so after that i got a set of 4 vac gages and went to town have not been sorry i did that . yes cost is one thing but to be honest i also found away to do it by justifying the cost of them against the carb rebuild from water in the motor to the frustration of using them and I live on a fixed income from social security disability so thing on it be for you do it