Hello, I am brand new here and plan to race a Yamaha R7 next year. I'm currently making a list of simple mods that are legal (race plastics/light removal/ECU tune [I think]/air filter with stock sized opening/exhaust). One thing that has me hung up: z) Aftermarket screw off type gas caps are allowed so long as they do not increase the orifice size compared to the stock cap. Are quarter turn caps allowed (TWM or similar), or does it have to *screw* off--like a Vortex (coarse thread cap)? Maybe I'm overthinking this.
You're overthinking it. 1/4 turns are fine, the opening limit was for production/superstock rules for endurance anyway.