Issues with sync'ing carbs

[Steve]

You can't just arbitrarily set all the screws to a certain number of turns. Start rich (3 turns), slowly turn a mixture screw until the engine speeds up a bit. (If you have your vacuum gauges connected, you will see an increase in vacuum.) Repeat this for each cylinder. Please note that all the screws may not end up at the same setting. On my son's 650, if I remember correctly, one is about 2 1/4, one is about 2 1/2, one is about 2 5/8, the last one is at 3 1/2.

It does not matter that they are different, what matters is that they are set to the best setting for that carb.

Still puzzled by your idle speed setting at a certain number of turns in or out. I have never really counted turns on that screw, I just turn it until the engine runs.

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[mhobryan]

Appreciate your patience Steve. I should have been more specific; I initially used 3 turns out on the mixture screws as a starting point, and would would go lean from there, It appeared to have symptoms of being too rich (pop the throttle, and idle would dip and engine wanted to stall). However, I had the needles all the way down to 1.5 turns out - which would be a really lean setting. All the while the idle would hunt. So I tried the setting it 2 turns, and 2.5 turns out to see if I could get the idle to be more stable, and start tweaking the mixture screws from there.

I could never get the idle to stabilize, wanted to hunt regardless of mixture setting. Figure best to take the carbs off again and clean.


It held an idle at 1500 RPM long enough for me to get the carb's sync'd though, and was also able to reconfirm it held the settings from my sync from yesterday.

Will pull carbs tonight and report back.