TOPIC:

OK - I'll re-word this. In my case I calibrated all three gauges to a master gauge. When calibration of my three Sync.-gauges was complete these three gauges read the same as the master. Again: unless you man-handle, drop or otherwise have reason to believe a gauge for some reason isn't working correctly - there is no need to "re-calibrate". BUT it only takes 2 minutes to manifold 3 gauges (stick or dial) together and pull a vacuum to ensure all three read the same at the target reading. The critical aspect is ensuring that all three carbs sync to the same reading. Your specific engine /tuning/set-up will only provide the max. vacuum that all these parameters will allow the engine to produce. My carbs adjust to 9.5 "hg. per my gauges. Nothing more or less will provide a smooth idle. And that's all I care about. The gauges are purely for reference across all 3 carbs. Whether the absolute True reading is actually 9"hg, it's a moot point. The gauges are purely for reference across all 3 carbs.

My experience was that every time I got the old 4 gauge pack out, after rolling around in my tool box for a year or two, I had to re-calibrate the gauges (even if I didn't have to adjust anything - without checking, you don't know). I finally got rid of them and picked up a Motion pro manometer unit but was equally unsatisfied as I had to replace the fluid (non-mercury) every time I wanted to use it (again, every couple of years - problem is the fluid evaporates). I have a Carbtune now which is tolerable but still requires some fussing.

The beauty of the old mercury manometer was that they don't need calibration ever. Of course they're fragile and that's why I don't have one anymore - but I wish I did. You can build a pretty useful unit with some aquarium hose and transmission fluid and if I was more energetic I would but I'm not so I'll stick with the Carbtune for those rare occasions when it's required.

I have the Carbtune Pro, with metal rods. Here is my approach to it (just this one as I don't use anything else).
When I synchronize, I don't actually even look at any numbers. It would be fine with me if the scale didn't even exist. All I care about is to have all cylinders pulsate as close to the virtual horizontal line as possible at idle and just a little above idle. I treat this adjustment as visual reference only, and for a casual motorcycle I am sure that's perfectly enough. When revving up the rods might, and probably will, go up to unevenly different heights and at slightly different speeds. I ignore that and have no problem with it as they soon even up when leaving the throttle and it drops to idle. It is normal in my opinion, due to the cylinders being slightly different when it comes to compression for example. One might have a bit higher, another lower, and that multiplies and shows at higher RPM's. If that's drastic, I'd check compression's, and even better do a leak check. Of course, the next thing to achieve equality would doing a top end overhaul, haha, putting new rings, doing deglazing and the valves because some might be sitting higher some much lower. That would be one over the top and expensive synchronization! haha

One last thing regarding Carbtune Pro. Describing maintenance of the gauge, the manual says:

Important - Each rod, spring and washer must go back in its original position and the right way up.

This confirms that they are calibrated during manufacturing process and don't need to have it done later. Of course, if they'd be thrashed around or used thousand of times, they will wear and tear. But for casual use, I bet they would last a life time as is.

Ooops, I did it again!!! What can I say - I had a blast

Could anyone fill me in if this is the right way the wires go?

Can't confirm the wiring (looks correct) but the restoration of the tail-light looks awesome. !!