Throttle Sync

[A357man]

How do you verify that both butterflies are closing at the same time when doing a throttle synce? Mine are covered by air intake hoses and I do not know what tool to use to remove them or even if it is necessary. Thanks.

[aggieengineer]

There's no need to see inside the throttle bodies. What needs to be snchronized is the intake manifold pressure across the range of throttle movement. I bought a Twinmax, which connects to the throttle bodies and shows any difference in pressure. There are also various manometers available.

[Ken H.]

ISFA [/i]closing[/i], when the throttle grip is at released, both TBS should be on their idle stop screws. The key to sync. is that they both open equal. Not mechanically, but vacuum equal.

[A357man]

I did the twin max sync. How do I know if they are both at their stop screws? What should I be looking at?

Thanks!

[Ken H.]

The throttle cables at each TB wrap around a bell crack / pulley on the back side of the TB. That crank has a tab that comes to rest against a stop screw. It is toward the bottom rear inside edge. The bell crack should set on the stop, not be hanging off the end of the cable so to speak, when you are at idle. If is not, one or both of your cables is too tight.

[Albert]

The throttle cables at each TB wrap around a bell crack / pulley on the back side of the TB. That crank has a tab that comes to rest against a stop screw. It is toward the bottom rear inside edge. The bell crack should set on the stop, not be hanging off the end of the cable so to speak, when you are at idle. If is not, one or both of your cables is too tight.

 

Ken,

Are these TB bell cracks anything like the Liberty Bell's crack?

OK I'm leaving.

[A357man]

Thank you very much.