Posted by Sherman in Idaho [24.32.202.166] on Monday, September 23, 2013 at 18:31:24 :
I'm futzing with a Carter WA-1, which seems to be an unusually complicated 1-barrel carb with lots of little things that require parts to be pushed this way and that by very light springs. Anyway, under the removable cover there's a screw that adjust a needle valve. It's not the idle mixture, because that's in the usual place. The adjusting screw is right under a shaft, and so is hard to adjust, but it can be gotten to while everything is put together and the engine is running. Does anyone here know what that's for and how to adjust it? Is it a "high speed" mixture screw? Something else? Also, does anyone know how the "anti-percolation" valves are supposed to work and how to tell if they're not? They're little flapper deals like the valves on a clarinet.