Warning to all the tanker rigs out there.. loctite your bolts for your petcock mount! I was out this morning riding and the bolts that hold the mount flange on for the petcock to the tank backed out and drained most of my gas. luckily I didn't lose the oversized O-ring that was in there or I would have been totally hosed! To remedy, I got some 1/4"x20 allen head bolts, washers, and blue loctite. and the right size O-ring. when you go to put it back together, put the bolts halfway in, then thread the petcock on the flange, then snug the bolts. if you snug the bolts before you get the petcock on the petcock nut won't clear the allenheads. Maybe this is just a fluke thing for clarke tanks, I dont know. My 250 clarke hasn't had a problem, but from now on I am going to use loctite and get rid of the phillips bolts garbage she is taking a nap too big of O-ring. had to use my leatherman to poke it back in while out and about to get the fuel to not leak. correct size o-ring. Yeah, I'll try to go back and find the size # for you guys.