I tried the smaller pilots first. It will compensate for the rich needle to some degree but will leave the curb idle way too lean which forces you to raise the slides further to get it to idle, which then causes it to run off of the (overly rich) needle jet and foul the plugs.
These carbs only have an air screw to fine tune the curb idle. The air screw also effects the transition where you are running off of the straight part of the jet needle. So to tune them properly, you need to select a slow jet (pilot) that will give you the best idle with the air screws between one and two tuns out, then tune the transition by changing the diameter of the jet needles. With the larger needles I was able to step up to a #40 slow jet so that it would idle correctly.
To properly sync the slides you should use a dual vacuum gauge. I use an old mercury manometer (not sure you can buy these any more). They are simple, accurate and durable. With a gauge type sync tool I'm always worried that it's going tho throw the gauge out of calibration if it spits back through the carbs. That is no an issue with the mercury sticks, the column will bounce a little then come right back.
I did rig up an inexpensive gauge setup so I could monitor the carbs while motoring down the road.
I got two small in-dash vacuum gauges from Harbor Freight (on sale for $14.95) and a bezel from the auto parts store for about $5. Bolt the gauges into the bezel, zip tie it to the handle bars, and run vacuum lines down to the intake boots. Word of warning, these are very cheap and inaccurate. Before using them to tune a bike you need to hook them both to a single vacuum source and see how far off they are from each other. In my case the right one reads about 1.5" higher than the left, so any time I'm comparing the two I need to subtract 1.5 from the reading on the right gauge.
To set the idle speed with vacuum gauges, you will adjust the slide stop screws so that the vacuum readings are even and the idle speed is about 1200rpm. Turning the screws in (clockwise) will raise the slides which will decrease vacuum and increase rpm. The screws are very sensitive, the slightest movement will greatly effect the vacuum readings. It's kind of a juggling act but once you get the feel for it you can dial then in with little effort.
To set the idle mixture with vacuum gauges, turn the mixture screws on both carbs in 1/4 turn at a time (waiting several seconds between each turn to let the motor settle) until you get the highest vacuum reading. If the vacuum is going down then turn them out 1/4 turn at a time until you reach the highest vacuum. Turning the screws in makes it richer, turning them out makes it leaner. Once you have found the best setting, turn the needles in completely until they lightly seat, counting the number of turns. If you are at less than one turn then the slow jet (pilot) is too small. If you are over two turns then the slow jet is too large. As stated above, if your jet needles and pilots are too far off it will effect the curb idle which would render this procedure useless.
To set the cables with vacuum gauges, hold the throttle just off idle and adjust the cables so that the vacuum readings are even. I will try to always turn the adjuster down (clockwise) on the cylinder with the lowest vacuum reading, rather than turn up the cylinder with the highest vacuum reading. If you turn them up you could remove all the free play from the cable which will throw off your idle sync. If everything is working properly then the slides should be synced for the entire throttle range. It's hard to test this when the bike is stationary because there is no load on the engine so you will reach redline with very little throttle. That is where the handlebar mounted gauges come in handy. When going down the road, the gauges should always move in unison. With the Mike's cable, this did not happen.
anyway, whatever they are, they seem to be giving good results
