TOPIC:

In 'old' times I've heard they supplied mercury in those tools. Now, the Carbtune has stainless steel metal rods inside the tubes. It really worked well on my other bikes.

biltonjim wrote: The last time I synchronised any carbs was when I did those on my XS Eleven. I've never used the gauge-type set up for doing the job, opting rather for the mercury column type. I believe these give a steadier visual indication of the vacuum levels, but I'd be interested to hear if anybody else has an opinion on the merits of one type over the other.

IMHO the individual gauge types are a pain as they need to be calibrated with each use while the fluid manometer type are self-calibrating. I've had all three types, gauge, fluid and Carb Tune (which uses metal slugs instead of fluid). The fluid was the easiest but since mercury's not an option any more, the new fluid evaporates and has to be replaced - also a pain. Now I use the Carb Tune - no evaporation but some calibration is required as some springs are involved.

Thanks for your comments, Bucko. In that case, I'm glad I've still got my six-column mercury type.

A bit off topic, but I remember playing with mercury when I was a kid. A magical substance! All the body temperature thermometers had mercury - until they broke
Quite a heavy metal as well.

Once a Gauge has been calibrated - that's it. We're talking about general purpose gauges here - NOT aviation/scientific/lab instrument gauges which require recalibration/recertification at regular intervals..
So - a gauge does not have to be re-calibrated before each use. Unless you drop it a lot !

scotch wrote: Once a Gauge has been calibrated - that's it. We're talking about general purpose gauges here - NOT aviation/scientific/lab instrument gauges which require recalibration/recertification at regular intervals..
So - a gauge does not have to be re-calibrated before each use. Unless you drop it a lot !

The absolute calibration doesn't matter - the problem is the gauges need to be calibrated to each other and unless you check them each time, you don't know if they off from each other.