I have the same gauges and have always calibrated them the same way you've shown. I've used them to synch the carbs on my GS850 and GS750. Both bikes run extremely well. Those gauges are perfectly adequate for the job, and are a great value. I would recommend them to anyone who has a multi-carb bike.

Many thanks for your video. I bought a set of these last week and wasn't sure if I had bought rubbish. Thanks to you I can sync my sv650 carbs with confidence. Thanks Mark

The answer I needed, including a simple demo. Good work!

Nice, clear and informative. I do have a set of vacuum gauges and also calibrate them before use which gives me peace of mind. Thx for sharing I'm sure this information will help a lot of people venturing into the world of Throttle body/Carb - Syncing/Balancing.

Thx, for once it is NOT a lengthy video. Perfect. Very informative. Greatly appreciated.

Awesome content, brief yet informative 👍 you just earned a subscriber!

It's funny I just bought a set of gauges to do sync work with and decided to test and see how close they were to each other, and I did the test with my mightyvac just as you did. Great video, thanks!

This was very interesting. I didn't realize you should check the calibration on the gauges before starting. So I did. Could see where I had gone wrong. Yesterday I synced the 4 carbs on my 1000RX perfectly. Great help from this video as from others I've looked at.

Thanks for doing this cleanly, concisely and thoroughly. Great video Thumbs up!

Great video sir. Very useful with solid information. Congrats.

I'm looking at these gauges. Good information. Thanks

Thank you Urban Monk!

Thanks for clearing that up

Thank you for explanation for plastick valves :) my gauges are dancing and I didn't know why :) thank you soo much !

Good video, I went to a tech school and have the same set as you and set them the same way. In class we had aircraft mechanics that insisted on the $1200.00 digital gauges but didn't work on all engines so I am happy with them. They work great on my old V65 Magna, Bmw, outboards, anything I try. A tool is only as good as the operator!

I'm on my daughter's KZfaq account. The actual guage reading is not the main issue. The main issue is if all 4 guages read the same with the same vacuum applied. I would get some vacuum fittings so I could hook up all 4 quages together. Then apply vacuum the the vacuum line. If all 4 quages read the same then they're accurate in a sense to dial in your carbs. Who cares if the actual vacuum is 13 inches but all 4 guages read 15 inches? You'll still be able to tune the carbs.

Great video. Intelligent and to the point. Thanks for uploading 👍

It’s best to calibrate to match the gauges at say 10”H2O vacuum not zero. Bikes typically pull 10-12” vacuum and it is best to be most accurate at that vacuum pressure.

Excellent video, thank you ever so much sir!

Extremely helpful!

Thanks for the info. on the gauges Brother!👍👍👍😎

thanks for the tips....i bought yesterday this sync kit .....

If you don't have the vacuum pump like yours, I have the same one. You can hook each gauge up to the same carb on the bike. And get the reading on one, then the next until you have tested all 4 on the same carb plug. Plus if yours can't be adjusted. Just note the difference between each gauge. Be it 1 lb or 4 lbs of vacuum. Then you can add or subtract to make all 4 the same.

great video tutorial, find very useful info !!

Great video thanks

Thank you!

I have the same vacuum set to use on my VFR800, it's fuel injected but need the starter valves setting. Number 1 cylinder is the reference so 2, 3 and 4 are adjusted in relation to that. I calibrated my set by noting no. 1 reading with the engine running and then set up gauges 2,3 and 4 by connecting to cylinder 1, one at a time and adjusted as per the video.

That was a great video with plenty of good information. Those cheap vacuum gauges have been around for years, and are very hit & miss as to their accuracy in relation to each other. It appears that you had a good set. Luckily I still have mercury gauges. I remember years ago a customer bought a set of those gauges because he fancied doing his own carb sync. He had a Yamaha XJ900, and I balanced the carbs using his gauges, and without stopping the engine I swopped each cylinder to my mercury gauges one at a time. There was a 9cm difference. Obviously it ran much better when I balanced it using the mercury gauges. I did exactly what you did and linked all the gauges together using T pieces and tubing, then applied my vacuum pump and adjusted the gauges until the needles all read pretty much the same. We balanced his bike using them, and again swopped over to my mercury gauges. There was a discrepancy of roughly 20mm across the 4 cylinder which is pretty damn close. For as you quite rightly say a minor difference won't be noticeable. So these cheap gauge sets can be accurate enough, and I suppose if one didn't have a vacuum pump one could use one cylinder of the engine to adjust the gauges in relation to each other, but it would be a bit of a 'faff' as we say over here. All the best.

They work for me!

Top job, best wishes to you & your wife♥️

Great intro music!

have you compared the vacuum ones to those with an electronic reading? which would you say would have a better accuracy?

i have an high quality gauge (single) from the 80s.then using the same cheap set you have there.they are within a half inch of vaccum of each other when i compared them.thats good enough for me.just NEVER drop them.

hi - just hooked the same gauge set up but the needles are nuts- what switches are those? im thinking of grabbing 4 shut off valves from the gardening section, will that work?

A bench sync works well. No cheap gauges needed.

to bw honest you dont even really need to sychronize them just set the air screws to the same, what the manual says, usually 2-1/4 turns and set the throttle so they all open equally at the same time, most the time the throttle never needs to be adjusted, just air and idle screws

what are the call the small tiny valve at tube hose sir?

Look forward to the actual synch!!

is the internal diameter of the adapters to attach to the port, important? I have 4 adapeters of the same type, but due to manufacturing imperfections, its internal diameter is not the same in all 4. I can appreciate this fact by blowing inside with mouth; some are more "free" than the others.. thanks.

Can I still use this method if I have accidentally tried to move the needles back by hand???

Man...mine are new(sincro tool kit) but come without valve and bouncing like crazy 😒 lost my mony..its. Imppsible to use...thanks for the advise 👍

Where can I get a set of those plastic inline valves?

Can you get them in 6 vs 4? Thanks. ✌

physics is always accurate

How to test gauges if you don’t have vacuum tool

Make sure the tubes are not dry rote.

I was going to buy these but the Amazon reviews are 50% negative... Don't want to risk it yet.

Not for nothing but the title is, "are they accurate?" You have shown that they are clearly in sync, but you haven't shown if they show te accurate level of vacuum. Are they registering the same vacuum as shown on the Mitey Vac?!

All the comments are theese are based on the fact you have enough of a brain to syncronise them to a single vaccum source and not to reley on them straight out of the box.! if you have the mentality to sync carbs you shold not assume they are perfect as none are and they will be all you need to do a great job!!!

Take em and toss em! Then go get em again toss em again! There is a perfectly good reason for them to be cheap. Also may I point out that the little valves are not also equal. Found that out hard way. Bottom line, don’t bother! More moving things are nothing but more things to go wrong! Hydraulics doesn’t lie!

why are everybody putting on that annoying music, cant watch this :(

Cheep almost always is cheep ! And nothing else !