If yours is leaking from all the screw plugs, mine did, use a little medium Loc-tite on them. A small torch soften it right up if you need to remove them. Use just enough to cover the threads. Mine still drip just a touch from the throttle shafts even with new bushings and shafts, it's just the fuel we have to run.
And as Jon said, the old idle jet needs expanded out on the tapered end to make a new seal, a pointed scratch awl works good and doesn't take much to expand it back out. A fellow on Ebay, ICERACER seems to always have W-1 parts if you take the time to hunt them down.
Metering rod adjustment is critical, just .050" difference is enough to feel. Higher up is richer. I run dual W-1's and this past fall, the rear carb quite idling, up in the main body is a small brass plug with a very small hole drilled in it. Mine plugged up, I couldn't get it pulled out, so I drilled it out very carefully. Since I wasn't sure about the front carb, I managed to get it's plug out, took measurements and made two new ones. The truck now runs like a top. I had to make a fixture to make new copper plugs for the housing using copper wire electrical wire. It was fun few days making stuff and well worth the trouble.
