[exavid]

imported post

Mag, if you have any binding in the float and it's pivot it's not going to be possible to get the carb working right until that's taken care of. Are you sure the pivot pin is straight? If you need to straighten it, do it on a hard flat surface by tapping it with a soft hammer, it should roll smoothly on a flat surface such a a sheet of glass on a very slight incline. You don't want to enlarge the holes in the casting, if the pin can move side to side in the carb the float level will be impossible to set. I would figure out the tight pin and then reset the float level so that it's the same as the other three carbs.The fact that you have to keep the throttle open a bit to idle does sound like the idle circuit is pumping in too much fuel, most likely due to the float level being high or the float valve not quite shutting off.

 

[exavid]

imported post

It would be difficult to correct the alignment of the bores in the carb casting without a straight reamer of the appropriate size, however if you could find a drill bit of the right diameter and push and twist it through, by hand, it's unlikely you'd do any damage and might be able to line things up. You'd need to run the bit through both holes to keep it in line. Other than that, a jeweler's file and a bit of judicious filing in the float's pivot might do the job. I'd try a little bit of both until I got the bind out. Unless you can get the float moving freely it isn't gonna work dependably. Any bind at all is going to change how high the float rides above or below the fuel level.

As for the spark plug readings, it take quite a few miles for any definiteshow in color unless the carbs are really way off, soot and white from over leaning can show up pretty fast, but a little bit off is going to take some time to show.

 

[exavid]

imported post

Sure could be. The other three carbs are okay?

 

[exavid]

imported post

Glad to hear you cured your problem. :clapper::clapper::clapper:

 

[exavid]

imported post

mag wrote:

The #1 float drain screw still leaks, which is odd, because it was at rest overnight with petcock off. Makes me think it's not from overfilled bowl, but just an old o-ring.

The carb drain screw would leak regardless of whether the petcock is open since the float bowl is vented. A small leak can make a surprising difference in mileage. How free are the wheels, can you spin the rear wheel when it's on the centerstand and the front wheel when it's off the ground? Any drag there would reduce mileage.

31mpg is a bit low, but maybe it will improve as you ride it. At least is sounds like she's running well now.