Issues when vacuum syncing

[XXV]

So I bought a vacuum sync. I cleaned the carbs, adjusted floats, bench synced, and the bike runs. I took it for a spin and man is it fast.
It is running a little rough so I bought a vacuum sync and attpted to sync. I can adjust three of the carbs together, however the carb (cyl 3) which doesn't have a throttle adjustment screw, is quite a bit off. I pulled the plugs. Plugs for 1,2,&4 were a nice, clean black with a great tan color on the firing tip. The plug from 3 was a little fouled. Too rich. Then I ran out of time (the story of my life with this bike). So I guess I'll close (tighten) the mix screw a little bit and go from there? Any other suggestions on the best, most efficient way in which to proceed?

[natemoen]

#3 carb is your static carb. The carbs have to be adjusted to the #3 carb. The screw down between #3 and #4. Adjust #4 to #3, screw vetwee #1 and #2 adjust #1 and #2 to match, and the screw between #2 and #3 adjust #1/2 pair to match #3/4 pair.

[wingnut]

The sequence for sync is to adjust 1&2 to match using the adjuster between the 2 carbs. Then match 3&4 using the screw between those 2 carbs. Then match 1&2 with 3&4 using the screw between 2&3. Also sync at the lowest rpm you can keep the bike running at. The sync will not affect the plug color unless you are way off. After you sync it go back and readjust the idle mixtures using either the idle drop or highest rpm methods. After that check the sync again and adjust again as nesasary. Try that and let us know how it turns out.

[wingnut]

Nat you must type faster than me .

[XXV]

Ok..well I know about adjusting to the 3rd carb, however what I am saying is that if the reading for the 3rd carb is way off, essentially I am adjusting the other carbs to be way off as well.

[wingnut]

During the sync process you don't care what the reading is. Just as long as all four are close to the same. If your number three is not running that could be a problem. Correct that issue, adjust the idle mixture or float hight, whatever the problem is. Verify that #3 is firing using the water on the pipe test adjust the idle mixture to obtain the highest rpm and try a re sync

[natemoen]

How did you decided #3 is "way off" then?

[XXV]

During the sync process you don't care what the reading is. Just as long as all four are close to the same. If your number three is not running that could be a problem. Correct that issue, adjust the idle mixture or float hight, whatever the problem is. Verify that #3 is firing using the water on the pipe test adjust the idle mixture to obtain the highest rpm and try a re sync

Well the carb gods took it easy on me. I am not sure why #3 was off, but I inspected the float height again, cleaned the spark plug....and I got lucky when it then ran much closer to the others. I adjusted all four and it seems to be running well. I took it for a ride and voíla. These bikes sound/ride great!