Recommendations on carb sync tool

ThatGPzGuy wrote:

I have a Carbtune and it works well, much better than the dials. Recently came across this that I might try:  Digi Sync  
 

I bought a small (two-carb) Digisync to try on the 440s. I'm looking forward to using it but who knows when that will be 

I look forward to that report. Perhaps this afternoon, just because 

 Back in the day, before I had carb sync gages, I would use an aquarium pump gang valve connected to an automotive fuel pump/manifold pressure gage. Since adjusting one carb has an effect on the others, and you could only see the effect on one carb at a time, It took a lot of jumping from one carb to another, but in the end, it got then synced.

 

 

We used to have a 4 channel DigiSync but it was difficult to use with the constantly changing numbers. 4 gauges in a row is visually much easier to use. It's easier to see when you have all 4 needles all pointing in the same direction. We sold ours.

I find the Mothion Pro SychPro works well:

 

 

   We're have both a 4-channel Morgan Carbtune and a Vance & Hines(?) 4-column mercury stick vacuum manometer set from the day.

   As analog devices, mercury sticks offer slightly greater resolution, but require an accurate method to reduce vacuum pulse flutter.  We use an idle jet inserted into each hose end to eliminate absolute vacuum reading variations column-to-column that might be induced by manually adjustable valves.
   The Carbtune device seems inherently self-balancing between channels.  The plungers operate in very tiny discrete steps, sorta digital, wherein mercury sticks are more like a continuous analog device.  The differences are fairly small, and likely only discernible at idle.
   Quality analog dial gauges that can be individually calibrated using a known vacuum source are fine.  They too will benefit from using an accurate, known-constant restrictor, such as the orifice of an idle jet in each hose to reduce flutter.
   Our experience with cheap vacuum gauge sets that lack calibration abilities have been poor.  Using a hand vacuum pump to draw say, 8 In. / Hg on cheap analog gauges have resulted in observed discrepancies of up to 2 In. / Hg between gauges.
   We have no experience with the Motion Pro Sync Pro liquid manometer.  The manual indicates that the liquid can be drawn into the intake tract under certain conditions, such as if the throttle is snapped shut from high RPM.  Chatter on other forums indicate it's happened.  Read the manual before deciding to purchase.

   We have a 4-column PCCC-labeled mercury stick set that has a full tank of mercury & good hoses for sale.  We acquired it in a parts lot from a defunct local bike shop we participated in a buyout from a few years ago.  We've taken it to Mid-OH the past two yrs. but it hasn't sold.  We will not attempt to ship 'cause we don't want to deal with draining & packaging mercury.  Local pickup or Mid-OH only.  PM if interested.