Universal Vacuum Carburetor Synchronization Balancer Gauge Carb Synchronizer Adjustment Tool Kit Compatible with Motorcycle BMW Honda Yamaha Kawasaki Suzuki GS KZ XS CB 550 650 750

These work great and are very accurate with the adjustable vacuum restricting valves, the adjustable zero on the gauges are a bit tricky to get to because you have to remove the glass faceplate to get to the screw! I would do the upgraded model if I were to buy them again but these will do for my usage. Great value, easy to use, stores easily, looks great and both to do the job intended!

Well made, and easy to use.

Worked well. Open bleed valves before zeroing gauges. Had to go back again because one still had some vacuum on it when I zeroed, but overall good tool for the price

Works great, has been a huge help in balancing carbs on bike.

Worth it. Compared the gauge readings to my coworkers snap on vac gauges and was spot on. The calibration is simple. Tips 1: having longer rubber hosing is great to be able to hang the gauge cluster on something other than the bike. THE GAUGES MUST NOT VIBRATE OR SHAKE FOR ACCURATE READINGS 2. Order a small fuel iv bottle and some kind of stand for it. Don't try rigging your gas tank just take it off the bike. 3. Get a metric Oring kit on amazon or Harbor freight. The orings on the carb extension tubes were kind of cheap and squished in a not good way.

These gauges were much bigger than I realized, about 4" diam. The valves stabilize the needles very well and they weren't too far off from each other when connected to the same vacuum source. Hoses could be longer but are adequate. The brass adapters are great. It seems built well and has made tuning 2 of my bikes much easier.

This guy works pretty good, take your time to fiddle with the vacuum adjusting knobs near the manifold, you want the guages to respond to your throttle blips without oscillating so heavily that your values cannot be read. Use your FSM or FOM to find your synch procedure. The older the machine the more frequently you will find yourself synching, the tension springs on the synch adjustment screws will start to provide slightly less force on their screws as they age. I do my 1987 two or three times each season, helps your cylinders and engine wear and provide power evenly.

The glass comes off when you remove the caps to synchronize the gauges