Dana Carvey -- I'm DOWN for Another 'Wayne's World' Movie!

Prepare the monkeys ... to fly out of your butt ... 'cause Dana Carvey tells TMZ he would totally sign on for another "Wayne's World" movie!!!! With one minor catch ...

Carvey was in New York City yesterday when we asked about a 3rd WW -- and Carvey replied, "You're gonna have to ask Mike [Myers] ... he's pretty busy, but yeah ... I'd do it if they want."

Carvey joked, "If they want, we can play 'em in their 50s ... 'Wayne! My prostate's enlarged!'"

It's not totally out of the question -- Carvey and Myers reunited for a WW sketch on SNL last year.