Vacuum Carburetor Synchronization Synchronizer

I'm glad I purchased these gauges! I had actually attempted to cancel the order after buying them, and was going to try adjusting my carbs without gauges first. The order was already shipped, so I decided to just keep them and try them out. I had already adjusted my bike's carbs just by ear, listening and adjusting until it ran the best, while I waited a couple of days for the gauges to arrive. When they got here I connected them up just to double check, and found my high speed sync was very near perfect, but the low sync was quite a way off. So I started over and synced everything up the proper way this time using the gauges, and man does my bike run great now! :)As for the gauges, I can't compare them to any others since I've only used these. They seem to be made well enough, pretty much what I expected. The hoses included are plenty long enough. I hung the gauges on the handlebars of my bike, and had plenty of hose to reach both carbs. (It's a V-twin cruiser, VS800 Intruder) The brass fittings screwed right into my carbs. Having one long and one short was nice, the short was was a perfect fit on one carb, while it was nice having the longer one for the other carb to clear the frame on that side. It made attaching the hoses easy! The gauges bounced around quite a lot, too much for an accurate reading, so I installed the little plastic restrictors in the lines close to the gauges. They worked well and were easy to adjust.When I started to sync my carbs, I first checked the gauges calibration by noting the reading on each carb, then swapping the gauges around and noting the readings again. They were close but not perfectly matched, so I opened the gauges and used the adjustment to get them perfectly matched. The clear face just unscrews off the gauge, then the flat head screw inside adjusts the needle. It's quick and easy.I may never need them again, but they've already paid off and were worth the purchase. If I ever need to balance dual carbs again, I know they'll do the trick! My only regret is maybe not buying the 4 gauge set, but then again I'll probably never own a 4-carb bike... lol

shipped out quickly. They do seem to work well......but I do question how perfectly calibrated they are since they don't measure zero exactly the same. They were very helful in getting my motorcycles twin carbs in sync. Bike does run better thanks to this affordable tool. come with vacume lines and in line adjusters to reduce the flutter on the needles.

This is a tool and works as it's designed to work. The blue plate the gauges are mounted to is metal. The face plates are plastic and it would be nice if they were glass, but if they were you break them and bitch about that too. So they did you a favor. ANY precision tool needs calibrating prior to use. Vacuum fluctuates and the needles are suppose to bounce rapidly. The tool is working as designed. The bouncing is actually a diagnostic aid of what is occurring in the engine and can be used to diagnose internal engine functioning. The restrictors are added to limit the bouncing of the gauges because you're using a vacuum gauge for something it was never actually designed to do. A manometer was designed to sync carbs. Back in the day manometers were expensive and there was also the obvious issues with the mercury. Someone came up with the idea, hey I could use a vacuum gauge (which every good mechanic already had) to do the same thing and get it close enough. Then someone with a brain came along and said lets try and limit the bounce of the needle and see if we can make it more accurate. Wow, look at that, it works! This is a quality tool that in the proper hands works as it's designed to work. For the most accurate results the resistors need to be installed and the gauges need to be zeroed to each other.

Gauges shipped and arrived on time. The gauges are well built, easy to read and display nicely. Syncing the two gauges to themselves was done easily by removing the cover, setting pointers in their appropriate locations, then using fine adjustment screws to set both gauges up exactly on a common vacuum source (IMHO, this should be done before using on any sync gauge set). Once the fine adjustments were made the gauges worked perfectly and allowed me to easily sync the idle speed and idle mixtures on my SBC’s two four barrel carbs. The gauges are a nice addition to my tool box.

Instructions are awful; this product assumes you are syncing a car's carb set.For motorcycles - completely disregard the text located around the inside of the gauges. Pay attention only to the numbers and the hash marks. Ignore the improper valve timing etc., this is not accurate.For the amateur or DIY'er, the instructions are wholly inadequate. You must cut the hoses close to the gauge itself, and install the dampening valves. Using the knob on this valves, make very slight adjustments until the wobble is *mostly* removed from the needles, do not attempt to stop the needles.They served their purpose, but the instructions are useless. Needles stick occasionally. Lacks the fine control and calibration needed to perfectly sync a carb set. Decent, but would not recommend if syncing more than 2 carbs. Not worth the frustration. Shell out a couple extra bucks for a set of 4 and it will make the job of syncing exponentially quicker and easier.

Kit has everything needed to do a single, twin cylinder, or an inline 4 if you know what your doing. Great price, quality materials, and much cheeper than paying someone for such a simple task ! Don't be intimidated, instructions, plus tons of instructional videos online. You'll ask yourself why you didn't have your own set sooner !!!