Carb Syncing: How to Fine Tune Your Carburetors 

►► Here is my step by step Twin Carb Cleaning tutorial - www.themotorcyclemd.com/inline-four-product-options

One thing i learned. Before you connect all four gauges to different carbs you should connect all gauges to one carb to make sure they are reading the same vacuume. they can be off and you'll have to compensate on your adjuster.

I sure like this kid... He's as thorough as it gets. Once you see a video of his, you rarely have questions.

This video taught me more about carb syn in three minutes than hours of other videos. Thank you

Probably the best tutorial on CV carb synching on RU-vid. Top man.

Cody I bought a 1980 cb900 it has a gsxr750 engine fitted its been sitting in a shed since 2001 carbon were full of jelly your video's are great all I need to know to get jobs done never had any trouble with cars till I bought this all the best keep making great informative video's

Your not wasting my time with the extra information its great!. Like the way you go about your work. "I like to get em perfect".

dude. amazing video. totally understood everything the first time youwent over it and was able to sync up the carbs on my 1993 nigthawk

I know you posted this a while ago, but I hope you see this message anyways. Recently I bought my first street bike. I've only ever had dirt bikes before now, so I've never been familiar with anything but one cylinder. I noticed very bad gas mileage after riding my bike around for a couple of weeks. I took off the carb rack, cleaned everything out, and adjusted the throttle plates. I had no idea what syncing the carbs were until now, after I've already put everything back together. It's such a relief that I did something right, granted without the perfect tools, and adjusted something for the better. Now in hindsight, because I actually know what syncing is, thanks to you, I'm so glad that I adjusted those plates, because they were MILES off a proper setting. Thanks you again so much.

I’ve been using CARBSTIX Mercury gauges for many many years and I love ‘em. BTW on these Japanese bikes those screws that appear to be Phillips head screws are NOT! They are JIS screws, Japanese Industrial Standard which is why everyone strips them out using Phillips head screwdrivers. Excellent work BTW and I believe I’m going to get a set of those sync gauges, you’ve convinced my 60 year old self!🤘🏼

I'm working on a Yamaha 50HP outboard engine with 4 carbs. This video really helps more than motorcycles! Thank you.

Mate, absolutely brilliant video. The comparison between vacuum and mercury was interesting, and a full description of why and how was invaluable, I am now a subscriber.

Great video. I guess we all have things we hate doing, this has always been one of mine, carb sync and spoking a wheel.

I just picked up a guage set from a guy retiring from boat motor wrenching . It's got about 6 different sets of vac needles all labeled 25 bucks . The carbs you rebuilt for my 78 cb750ss are doing great . Awesome job ! . You said I should sinc them . 2k miles later I will thanks to this video . It's almost riding weather bro , let's GO. Thanks again .

one of the most simple and easiest to understand explanation of syncing carbs. Thanks a lot mate you've helped me out a lot

You have a real easy way about you which is thorough and complete. Keep up the good videos.

What a find! Yes its from 2016 but this is the cool thing about YT. I've been working on bikes for 30 years now and this is, by far, the clearest explanation yet. I've got this to do, just rebuilt the carbies on my 1985 GS850, she starts, idles with a fart and a pop but isn't pulling much above 3000rpm. Carbs were bench synced only so I'd expect nothing less than dog rough! You're a gold mine, if only to confirm what we know (or thought we did!) Love you man.

I love this video. You went over how the carbs work, how to fix it, and what are things to know. How you explain things, in order and what to watch out for is awesome. You answered questions i didn't even know i had, and things like the base carb, never knew existed. But that makes sense. Awesome video, Instant sub. Keep doing what your doing.

This guy knows his stuff. I've always used the mercury gauges. he gets it right.

Definitely useful info here, short and sweet too, carb balancing has been a mystery to me for years but after watching this it makes total sense

Dang, just found the channel and subscribed, but looks like I'm about 7 yrs too late. Great video!

If you calibrate the gauges to each other they will have more accuracy. All you need is a syringe and 4 port manifold to create a common vacuum, then use the calibration screws on the affected gauge. Best to pull the vacuum to the normal operating value during cal-in your case around 20 cm/hg. The cheap Emgo gauges have a cal screw under the glass. If the gauges don't have adjustments then note which are off or mark the bezel for error correction. You also need to dial or damp more bounce out of all the gauges.

Definitely not wasting my time. You are very thorough in your explanation. Much better than any video I've seen so far. But got only question. Shouldn't the valves be adjusted before this procedure? Brother keep up the great videos.

Hands down the most informative and professionally made motorcycle mechanics videos on the web. You def need your own tv show. Keep up the good work, im learning more from you than a combination of multiple other people combined. Great work bro, keep em comin.

Great Video. I have a 1982 v45 Magna, since 1984. I put it away in 1990 and just started to restore it again. Carbs seized and Shifter rod seized. So I tore it apart. Had the motor sitting there studying it for a year. If you ever seen the carbs for a V45 it would scare you. Looking at you video inspired me. I remember the nighthawks, unfortunately Magnas smoked them. Scared my brother in-law back then. Well Great Video Thanks. I will Show a video of the magna when I start that. Oh, in 1982 the Magna was way ahead of it time, Anti-Dive, Electric Fuel Pump, Water Cooled, Shaft Drive, Hydrolic Clutch and Brake, And probably the best bike ever made in its time. And So fast. Great Video, Your Awsome

Best video I've ever seen on teaching someone how to sync carbs! Put out an entire series of videos! Your direct, to the point and don't mess around with "so now I'm gonna loosen this screw...that's just not coming off is it" stuff. Thank you for such a professionally done video!!!!

Fantastic info. You saved me from buying a synchro kit for a recently purchased 1985 VF1000. After cleaning the carbs, everything ran better than Imagined.

You are a life saver. I am restoring a mid 90's Ducati and was looking everywhere to find where to attach my synchronizer!

This is the first vid of yours I've watched. It's given me a start on what I should be looking at with my G1 6R Ninja dying on me. Thanks for sharing your expertise. It's invaluable.

this guy is like a service manual for me. best information and tips

Awesome video. My english isn't that good but I understood nearly everything. If your not already an instructor you would be one of the best instructor ever. I wouldn't hesitate to take lessons. I immediatly subscribed to your channel. Thanks!

Thanks for making this video. I’ve learned more in this video in regards to carb adjustment and different types of gauges than I have in any other video on here.

what I learned how you easily set the sync without gauges is: remove the carb-bay from your bike take the smallest drill you can (one that is not grimy nor with burrs) get mark one side of the shaft with a Edding(or whatever permanent marker you can get) for repeatability of the position for the next step: BE GENTLE! using force might damage your carb fataly open the butterfly by turning the RPM screw in, so that the drill will juuust fit between the "Master"-butterfly and the carb-body with the mark facing up (make notes for the turns on the RPM screw) repeat with the "Slave"-butterflies so that the drill will juuust fit underneath those close the RPM screw back to normal by screwing it out insert the carb back into your bike and take a ride to warm up the engine adjust the idle to spec RPM

You explained the procedure well and I like that you showed the difference between both style tools to check the carbs. Everything was clear to see in the video. Thumbs up

I love this guy he explains everything so well. Thank you

Great Video! Still very handy in 2023! Just bought a 2004 Kawasaki Concours 1000 and needed this info!

Best instructional video ever, well presented, no unnecessary talk, great style , fantastic information. Told me everything I needed to know. Keep it up!

Marvelous level of detail - thanks!

I bought a 73 cb750 that had been parked for 43 years. Oil down the cylinders, carb clean, oil change, new plugs, air filter, cleaned points, got it running. It ran poorly, so I removed the carbs again and found a drill bit that fit nicely under one carb slide that I knew was working well. Adjusted the other 3 to match. Voila! I was riding! But a little sputter just off idle, where I do most of my riding bothered me. I built a manometer. Got them adjusted really close to the same. Now it actually runs a little worse. I'm buying some gauges today (quality used ones) and gonna try it again.

Cody thank Yoxford your video's they have helped me sort my bike out in stages now getting it ready for mot just wiring and odds and sods to do you demonstration on the balance gauges has given me the know how to set them carbs up to get them close I used a sewing needle to get them close as it was really rough to start with and wouldn't idle now it idles to place gauges on to balance keep the videos coming regards mark

You sound so knowing what you do you get yourself a follower

Best video I’ve seen on carb syncing. Thanks

Wow hands down the best video on carb syncing. I totally get it now. Took the fear out of this mystery subject. Love the channel!

Somehow i understand you better than most youtubers . Very descriptive love the vid

Thank you! Your videos save me a truck load of money and frustration.

Awesome video! Watching this video gave me the confidence to sync my 1981 cb750k. I too have the mercury gauges, and I wondered which gauges were better. You answered that question, and more. Thanks!!!

I drop a stupid port screw and washer down into the middle of the engine /EVERY/ time I do this. They are such a PITA to get back!!! New subscriber here and wanted to say you did a very nice job with this video. I noticed you have pods. I have a 93 CB750 and I know the reputation Nighthawks have running with pods. It demonstrates to me you really know what you're doing. Keep up the good work - really happy I stumbled across your channel.

You guys explaining things like a teacher , perfect, thanks a lot buddy.

Your video is the best.I will use your advice when I synchronizes my carbs today.

Depending on how the carb vacuum layout is you can have 2 banks of 2 carbs instead of 1 master carb. Keihin FCR's are like this. Carb 1and2 are tied together and 3and4 are ties to gether. With port linking the 2 banks of 2 together. You make 1&2 the same, 3 & 4 the same then bring both pairs together with the center spring screw.

This is exactly what I have been looking for. Even better is that it's the same bike that I've defiled for my own project.

Your mechanic skills are fantastic, but your teaching skills are beyond excellent. Keep up the great work!!!

Absolutely superb demonstration of spot-on, detailed, and pertinent carburetor synch process. ++Awesome++

Love the video MC MD. The clear no nonsense step by step tutorial is great, really makes it seem not so intimidating.

G'day from Australia Beautiful non-bullshit video, well done. Only thing I'd have added is an explanation about the base carb being directly connected to the throttle cable and is where the the idle speed is adjusted. Great stuff, thanks

Excellent explanation and tutorial. Could not be more complete. Congratulatons!

Good clear information thats why i subscribed . What would cause number two carby to flood cylinder, even when engine is running fuel is leaking out exhaust manifold . Fuel is also getting into the engine oil and raising the oil level within 5-10 minutes running time. I have checked floats on all 4 carbs ( multiple times ) new jets new inlet rubbers new hose clamps carb bodies cleaned ( multiple times ) . Its a 1981 gsx 1100

Thanks man, learned about this in school but needed a refresher, gotta sync 3 carbs on a Honda outboard

Just wow, I’m new to bike and have made a silly mistake with a bad manometer, hopefully my bike will survive the water manometer it sucked it in! YUP! Any way draining the oil and pulling the plugs for a few spins and hopefully I’ll get away with it !!!!! I’ve watched lots of online videos but NONE come near the quality and content of this one here. I have just subscribed and this will be my come to place to learn more IF my bike has survived.

Great editing Cody! The reason for the difference in the vacuum vs. mercury is the vac gauges need "sync'd" to each other before use. I do it every time I use them. I can share the link to my video on doing that if you'd like. Also note, the Mercury gauges need "sync'd" too. Its common the many folks (not looking like you do) store the gauges on their side and little by little small amounts of mercury (or the later used blue fluid) separate of leak out and cause you to think the carb are out of sync. The big point here is your carb sync is only as good as the gauge sync. Keep Wrenching pal...H2W

Great production value and teaching. I'm watching a bunch of your videos right now and learning so much!

hey man, just wanted to let you know that you present information is great. straight to the point and has warnings. my view was just a random click, but i will be viewing more videos and subing to your channel. keep up the good work.

This is by far The Best Video For Carb Sync! Thanks a lot!

Except tutorial , I’ll be doing mine today & you just took any worry out of it. Having never done this on a bike before.👍🇨🇦

Many thanks for a great lesson,i shall put this knowledge into practise when i balance the carbs on my cb400/4 (1977)

Easy listen to instructions and simple instructions, I’ll definitely be giving it a go . Cheers man

Lots of good info here man. I've come from 4wheel land where a two wheel friend wants me to rebuild his carbs and get his bike running again and I'm just going and researching everything I may need to do. So thank you. 👍🏻

This guy crammed about 3 hours worth of info into 14 min only focusing on important points and good insight on common misconceptions. 👍

Great, learning heaps, my only feedback is the conclusion that Merc was better than the gauges based on what we saw; adjustment by gauge, then throttle butterfly seating, then went straight to merc. I think that it would have been logical to go back to gauge for a reading before the conclusion. This may have been done off video, my contribution is simply about trouble shooting technique for us, not a doubt as to merc being better or his competence.

Hi there Motorcycle MD,thank you for showing how to sync the carbs,you explained it Excellently,thank you so much friend 😊😊😊

Brilliant video mate. Would have been nice to see what happens when the other adjustment screws weee moved. Some great points though 👍🏻

Such an awesome tool to have if your a daily rider -82 650 maxim it's a givin I have one of these

Yep, some old dudes from yesteryear used to sync with a piece of tubing by ear and good at it too

Best video / tutorial on carb syncin I have ever seen! Thanks for your effort!

Hi, I am really happy you made this video! And I understand that you have the Knowlege!! I Have just started a project building a Junior Drag Bike for my son, and are just now working with the Carburettors to get them to work. This is really helpfull!!

Good video, explains it well and its not too long.

I dropped a like just cuz i have a single carb setup but i as happy you didnt let me aste my time watching

great video bud cheers been sorting my own bikes for years never too old to learn new things picked up a tip with the snapping back the throttles simple trick but makes so much sence ;-) Respect fella ride safe

Just got my ‘95 GL1500 road ready, and will start on the ‘80 KZ1300 with 3600 original miles... yes only 3600! Rebuilt the carbs, but need to balance them now..

This is the best video I have ever seen ! Outstanding information, thank you

This is at least the third time I've watched this. Great content. The royalty free music though... it's loud in some parts of the video

You explained it very well my friend. Thank you 🙏

Thanks a lot man, this is the best carb sync vid on the 'net! I love all the extra info you add in, it's really valuable info!

I like the video. Thanks for your thorough overview of what you're doing and why.

Dude thank you so much for sharing this . I finally got my bike running the way it’s supposed to be than you thank you 🙏

Fantastic video. Explains everything perfectly.

you sound and look like a really cool guy to have around! and your videos are way more informative than any other ones I saw on YT so far, Thank you!

I always had a heck of a time getting Mikuni Jets dialed in correctly ive owned a lot of Bikes and watercraft and i never developed “the Ear” that the Professionals have i did however use a borrowed Vacumn Guage set to sync my old Honda 4 cylinder that was a 650 cc and I loved everthing about that bike as i felt it had the weight and ride of a much bigger bike mine was loaded with soft Saddle Bags a Sissy bar/ back rest and a luggage rack fo long distance rides the drawback to that bike was it was. A 1981 and that was the year motorcycles had to run with the headlight on. So many manufacturers just hot wired the head light with a modified harness and did not up grade the charging systems from the previous year. Production which resulted in a slow drain on the battery i had a Yamaha that luckily did still have a kick start but the motorcycle wouldn’t run worth a crap with a dead battery. I could tell by the sound of my electric starter that i needed to get the bike home ASAP to put it on a charger the dealer kept telling me there isn’t anything wrong with the Motorcycle after countless of times bringing it in to them it was frustrating my Honda 650].did not have a kick starter it was electric only or push start No real hills to speak of as i lived in South Florida

Man, this video is awesome, so simple explained, so clear. Congrats. New suscriber here.

Hi there , thank you for sharing your knowledge about carb synchronizing, can you please do a video on synchronizing carbs on a GL 1500 Goldwing . Thanks

just finalizing my bandit 400 carb effort. Many thanks, really helpful!

Fantastic video well explained reasoning and procedural steps with a concise and strait to the point you are now my go to for video person for motorcycle repair. Thank you K

Such an informative introduction alone

love your vids mate, it looks like the old school mercury sync gauge is more accurate than the new gauges. As mercury is a substrate that can't be altered, it's automatically in calibration, and perhaps the gauged calibration setup has gauges that could possibly be out of calibration? But as you said, you can get the synchronisation in the ball park with close tolerances.

Very good video . Thanks mate . That old bike purrs like a kitty …so good

You can still use the vacuum to get your pilot air screws to a good baseline or as a sanity check if you're investigating a rough running engine.

Excellent video, it should be watched by all who fear multiple carb setups. It would be great if those gauges had some sort of internal damper to stop the oscillations.

Best I’ve seen thanks

Nice Video ! Thank God for youtube , my ol'83 magna will soon be running like a champ once again .....

Very nice cb750. Thanks for the tutorial.