thing is bout the wt813, the hole on the back of the carb -the pump bore hole, with an ada manafold- not shure bout the stock one- when this 813 is bolted up, bout 1/8th of the pump hole is exposed. I break out the handy-dandy shoe-goo, with a small flatblade screwdriver- put it on the screw driver- very little- you donot want this stuff to go into the exposed hole- gum up the pump, let the goo set on the screwdriver for a little bit to thicken it up- then apply it to one side of the hole- then sorta pull the little blob of glue over the hole - and anchor on the oppsite side of the hole- let the glue touch the manafold too- better bond.- silicone sealant dissolves around gas- use shoe goo. - yea, this will make the bore wear trouble free. I do this everytime I bolt up the 813- And I do change- tinker with carbs often.