can anyone tell me what size tap it would take to clean up glow plug threads on my fa 56 saito

1/4-32 This is not a tap you can get at the hardware store. It is a NSS thread and would be special order.

However, they are sometimes available at the LHS. That's where I bought mine.

http://www2.towerhobbies.com/cgi-bin...?&I=LXL774&P=7

http://www.horizonhobby.com/Search/D...&OverallCatID=

Enjoy,

Jim

thanks jim looked all over for answer