You dont adjust the vacuum... you adjust the voes to react at different levels of vacuum.

 

The harley VOES is adjustable. You need to dig the silicone out of the one side and you will find a screw in there by turning it you can raise or lower the pressure that it switches. Once you have it where you want it you need to refill the area with silicone.
John

 

I never knew about that.

 

Now I'm shocked you didn't know that.

 

well i got the switch, it was only 15 dollars.
so if i understand this correctly, after i tune the carb, i need to adjust the ignition and the adjust the voes last?

 

You shouldn't have to adjust the timing unless it wasn't timed right to start with or the same with the carb just connect up the voes and you should be ready to ride. You just need to setup the carb if the air/fuel isn't adjusted right according to the pilot jet. If you have a 45 pilot and 175 or bigger for the main you should be good other than air/fuel which around 2 turns out should be good start.

 

I never took it apart.
I don't claim to know everything. If I don't know, I will not act like I do.
And there is always more to learn.

 

Set the carb to a decent starting point w/r/t jetting (someone else already mentioned 45 idle jet, 170 main jet, and 2 turns out on the idle mixture screw as a good starting point).

Set the ignition to the factory settings, install the VOES - and you should be in the ballpark.

If you've got a high compression engine and a larger cam - you may need to retard the timing slightly from factory settings.

VOES adjustments are only required if you experience pinging on low load/part throttle to WOT transition.

 

Yep always some new tricks to learn.

 

To properly tune an engine you set the timing first, then get the carb close, tune the exhaust if possible then play with the carb and maybe a few degrees on the timing. Whenever you change one it can change the others, especially on a built engine.
John