Before you go making changes to the carb, try this: With it running at usual driving rpm, 2500 or whatever it is at most, pull a vacuum line. Yes, create a vacuum leak. Watch the rpms, listen to the engine. If speed decreases, the mixture is now too lean and needs enrichment, more jet. If engine speed increases, you have too much fuel already, as additional air allows greater rpm with by burning that fuel better.
Having said that, I've found B's to be very rich from the factory. I've worked with mine to get it dialed in, it is now jetted down to about 2/3 what the original jet was. Do not do this without the engine telling you it wants it however. I was not able to find jets available to buy, so I soldered mine up and drilled it smaller. You can buy drills to do this at your local hardware store, meant for cleaning torch tips.
Devin
