will these work?

Found these on ebay, and was wondering if they will work to sync carbs.

vacuum gauges on ebay

 

Should work. You'll have to fab up a mount, hose connectors and restricters to keep the needles from bouncing.

 

Otherwise I was looking at doing THESE.

 

You would need to make sure that they read the same levels (calibrate them).
Easiest way would be to hook them all to a single vacuum source (via tees) and make sure they read the same levels on the gauge.
Otherwise, you are off from the begining and will never get a good sync.

Or, you could just use one gauge and go from cylinder to cylinder (very tedious)

 

Or - save up those sheckles and buy really good just once - get this:
Morgan CarbTune II

I've got the Morgan and what a great tool it is -- reliable, well made, never have to worry about storage or transporting it, etc etc etc.

Other than a ColourTune plug, the best money I've spent on tools.

 

j2) Morgan Carbtune Pro 4-column Synch Tool-Gauge-Stick....brand new, no display box, includes all accessories and instructions. This is the one that professionals use and recommend, and is superior in design, ease of use, and accuracy versus vacuum gauges and all other versions, whether fluid-filled or otherwise. Uses damped stainless steel sliding dowel rods instead of mercury or the "blue mystery fluid", giving accurate, safe, and easy-to-read measurements. More expensive than other synch tools and worth it. Use it even once and you'll wonder how you lived without it.

NOTE: this tool is used on all XJ engines, regardless of whether it is a "YICS" engine or not.

Also, please note! you can sometimes find these same sticks selling at a discount at various places, but most of these places are offering a much older, now-discontinued Carbtune II version, rather than the latest, much-improved Carbtune PRO version that is offered here. The PRO version is much more durable, accurate, and easier to clean and service than the older version.

HCP96Q Morgan Carbtune Pro 4-column Synch Sticks:
$ 114.00


j3) Storage/Transport Pouch for the above carbtune pro synch stick....very nice zippered and clasp-closure storage case to hold the gauge and all the accessories neatly and safely. You REALLY want to have this to safely store and transport the (somewhat fragile) synch gauges!

HCP1287 Morgan Carbtune Storage & Transport Pouch
$ 19.00

 

The problem with Gauges is that the Indicator Needle Arm is "Spring-loaded"

Since the Engine will be running at, (shall we say) 1,000 rpm ... the Needle will be fluctuating quite rapidly due to the Four Cycle Ignition.

Unless the Vacuum Pressure is HIGHLY Restricted ... The Vacuum is going to make the "Pointer" go wild between the rapidly fluctuating Intake stroke.
The unrestricted vacuum on the instrument will make the Needle display an inaccurate value as the fluctuating indicator overpowers the wound spring.

Even with restriction reduced to a passage with the Inside Diameter of a Carb Cleaner Spray Tube ... there will still be "Vibration" and a fluttering of the Instruments Display Needle that will contribute to the possible inaccurate reading that results from multiple gauges being uses and not calibrated.

To circumvent the possible inaccuracy ... it's best to limit how many Gauges are hooked-up.

This is why the shift went from Needle Faced Gauges to Columns of Mercury.

You would be better off taking the time to measure each Manifold separately, using ONE Gauge ... than relying on inexpensive Gauges that may not give you an accurate reading.

It takes a few minutes longer to sync a rack of Carbs using the One Guage Method.
You don't have the luxury of seeing all the Manifolds displayed at once.

But, the bottom line is accuracy and you can depend on the one gauge performing the same function four times rather than having four gauges showing you a reading that might be wrong.

 

Or make a manometer:

http://xjbikes.com/Forums/viewtopic/t=9 ... meter.html

 

I second the Morgan Carbtune. I have one and it is an excellent product. Small & compact.

I used the older mercury column set up back in the late 70's and it worked OK but not in the league of the Morgan. Leaking was always a concern.

The ability to see the vaccum readings on all 4 cylinders is critical when you are trying to balance the two banks of carbs via the central adjuster. Even a small adjustment sometimes means you have to go back and tweak a carb. Things wear on the linkage of these old bikes.

I've tried the cheaper way with individual vaccum gauges but because you can't restrict them properly the needles bounce all over the place.

 

I've used this tool in my shop for a few years. Very expensive but if you do any extra besides your own bike have them chip in each time and it will pay itself back.

http://www.klsupply.com/handtools/ht-ca ... ervice.php

No worry about mercury, restrictors, ect... - hook it to the bikes battery and you're in business.

Sean Morley