Pull the throttle rod off the carb lever and check the rpm.
Is it the same as with the linkage?
Is the throttle lever on the carb tight to the shaft on to which its pressed? Does the linkage all work smooth and free from binding?
Does the long lever around the back side clear the small cover over the accelerator pump?
Is the metering rod pivot under the metal cover tight to the linkage with no extra movement up or down?
How does it run out on the road? any other problems?
A tad more idle mixture screw might help along with a little more timing. With todays fuels, you can get away with more timing, which almost always makes them run better. Try bumping the timing three or four degrees, then readjust the idle speed and mixture screw. You have to tweak each of the three to get it right, and don't be afraid to jump back and forth from rpm to mixture once you set timing up a little. No special tools needed, vacuum gauge is handy, but you can do the same by ear. Listen for smoothest idle.
The mixture screw only needs turned 1/16 at a time, when you go in ( clock wise ), you go lean which makes them stumble and rough running, turning out ( counter clock wise ) will richen it up. This is where you can get into trouble as they don't really show any sign of being to rich other then smell. 1 1/2 to 2 from a light seated position is where it should adjust to, 2 1/4 at the most. Each engine is slightly different do to altitude, barometric pressure, fuel quality, and internal condition of the engine. My engine tune changes with outside temperature, so I am always readjusting ever so slightly to keep it where I like it.
Joe
