I pulled my breather and carb off to put on a new carb and saw some kind of sealer or silicone on the breather bolts when I put it back together what kind of sealer should I use on the threads of the breather bolts?
No silicone. You don't want that stuff anywhere near an engine and moving parts, oil passages, etc. I prefer just using some blue loktite on the breather bolts. If you've got a SE backing plate with the 3 washers on each breather bolt, use a very thin coating of Hylomar on the washers.