Tune-A-Fish said:
I would guess a 35 pilot to start with and 1/8 and 5/32 in drills use the 5/32nd to get the first up (round end not the drill end) then when the 1/8th slides under #2 easy they will be money.
As long as this works out to be a smaller throttle opening than that used for idle it sounds ok, but you have to know that for certain. This is what I do and how I understand the function.
"syncing" the carbs is intended to get both cylinders to produce the same output. This is rather tricky to actually test for and adjust, so we fall back to just trying to make everything be mechanically the same. To that end, we "synchronize" the throttles. We could do this by reading the manifold vacuum on each cylinder and adjusting the carbs accordingly, but that still does not ensure equal output. In this case, we adopt an even cruder method and endeavor to merely make the slides rise and fall at the exact same time, hopefully this results in even power output. So we place an obstruction in the venturi to exactly locate the throttle slides. Any obstruction will do so long as it is identical for both (or more) carbs. You could use a pair off 3/4" bits or a pair of 1/16" bits - the size is irrelevant as long as they are the same. Then it is a small matter to adjust the operating mechanism - in this case cable adjusters on the top of the carbs - so that both throttles begin to move at exactly the same time. Since they are presumably held open the exact same amount by our drill bit of whatever size, the fact that we get the slack in the cables adjusted so that both slides to start to lift at the same time means that they will always be in identical locations regardless of throttle opening. Idle setting is merely setting the lowest position of each throttle, and aside from the fact that we would like both idle stop screws to stop the slides in the identical spot, it is basically irrelevant for all other throttle positions.
I generally use the bottom of the slide bores for a stop, but using a tiny drill bit is more acurate. Why use a tiny bit? Because you want to ensure that you do not inadvertently adjust the cable so they become the limiting factor and render the idle stop screws useless. When the engine is idling, there needs to be at least a little slack in the cables. If the slides are hanging by their cables when the throttle is closed and not touching the idle stop screws, the cable adjustment will be setting the idle speed. If that position is 1/16" higher than what the idle position should be, your idle speed will be 10,000 rpm! In neutral, holding a very small throttle opening off of idle will send the rpm's off the end of the tach. I have some race carbs on one of my street bikes. Those carbs have no idle stops at all. Let go of the throttle and the engine dies, as the throttles can close so far the engine is just choked off. On the street, I get it to idle (sort of) by adjusting all the slack out of the cables and it becomes the cables that hold the throttles open far enough to keep the engine running. I can tell you it takes very VERY little adjustment at the cable adjuster on just one carb to sent the engine off the end of the tach. So it is fairly impractical, as normal variation in the cable operation makes the idle speed quite variable.
Jet size should not cause anything like this, nor the reeds - though the jet sizes should be fine at least to get it running and start tuning. I would throw away the jet from the rebuild kit and get factory Mikuni out of hand - would not even attempt to work on solving a problem without oem brass though I very much doubt that this is the problem.
Do make sure the float bowls are on correctly - they are NOT the same, and that the connector line for the choke is good. And make sure your slides will both touch the bottom of their bores with the idle stop screws removed. Fix the engine runaway speed first and then adjust everything and you can start tuning.
