Balancing throttle bodies

[julians]

Is there an easy way to check that the throttle butterflies are opening to the same amount. Can you just use a visible check or is that not accurate enough.

 

I'm thinking that out of balance throttle butterflies may be causing my funny idling issues (see thread 'cranking advance')

 

Ta

 

[oilyhands]

You mcan synchronize them by undoing the balnce screw and the idle screw, the take up the slack in the balance mechanism until the butterfly just starts to move. A better way is to use an airflow meter/synchrometer to test that each barrel is drawing the same amount of air, the cheapest synchrometer is a short piece of rubber hose and your ear, just listen to the 'thwack-thwack' of the inlet pulse, when the volumes are near the same between each barrel then the barrels are balanced.

 

Oily