Quote Originally Posted by pennyman1 View Post
These jet valve heads crack between the valves and can cause leaks in extreme conditions. Right now on ebay there is a posting for a non jet valve head for a forklift that is selling for 218 on sale - it is bare, but you could swap over the rest of your parts if they are still good. If the valvesare gone, the air port is already blocked - btw the air passage actually is feed off of the primary barrel of the carb until about 1/2 throt tle, and is fuel and air. A weber adaptor kit blockes the port off - if you really want to block the port - take the carb off and tap and thread an allen set screw with sealant into the hole flush with the surface of the manifold - thats how they have you block the ports when you install a weber kit, or at least thats how my instructions read. Mine has been that way for 29 years without problems.
I thought it was fresh air. We had the one guy that was blowing the hose from the side of the carb because the valve was stuck open. Perhaps it was a later model.