Originally Posted by uglybiker
Looking at the pics, you'll probably need a large. Measure the stem diameter where the grommet goes and the base opening. Then email them to the vendor. They should be able to make sure you get the right one.
Ya that was the plan... I need to find my measuring tape but it looks like a inch and half across. That or I was just going to order a large and a medium.
*edit I was also thinking of another purge Valve.