Hey guys, I'm prepping an 09 Night Train tank for a quick inner bath of some metal rescue to eliminate some very light internal surface rust. Bought the tank used and the check valve and other hardware has already been removed. I'm trying to figure out the size of the thread where the check valve physically screws into the tank. I'd like to throw a temporary bolt in there to seal it up while I clean the inside of the tank. The only check valve I have is still currently mounted on my bike and I'd rather not mount it before using the rust remover. I even tried a rather large 3/4" bolt and it's still to small. I'm thinking somewhere right around a 1" bolt might work but if anyone knows for sure please let me know! Thanks! Also I'd like to know if it's machine thread or coarse thread?

 

Nevermind guys, took the tank down to a nut and bolt center today. Turns out it takes a 7/8" bolt to plug the hole. Maybe that info will come in handy for someone down the line. Take care folks!