R90/6 # 12 Rebuilding Bing CV Carburetors

[@boxer2valve]

Download your copy of this episode to view anytime and anywhere. We now have Downloads of each episode and the entire series available through our website for a VERY small price! Why pay for a download? Not only does this help ensure you will always have access to this video but it also supports our video team with proceeds for video equipment maintenance and new production gear to help us create additional 2 Valve focused videos. Find the Digital Downloads and Parts Used in this video here: www.boxer2valve.com/r906-12-rebuilding-bing-cv-carburetors.html

[@kjenkins893]

A true pro!!!! You obviously are about excellence! The veteran tips of adjusting the floats, prepping the choke gasket, removing o rings, & removing the butterfly are greatly appreciated!!! Thank you!

[@boxer2valve]

Hello, It's good to know that you can benefit from what we are doing.

[@dianedownie5951]

What a nice man !

[@thesmallplane]

I am redoing an identical bike, and finding these tutorials absolutely invaluable. I started with the carbs and an oil change just to see if I could get the bike started, but now realize how much I SHOULD do before I even think abut riding. BTW, this is very much a barn find, too, so probably better go through the whole thing.

[@SoniaInternational]

“It’s a lot of work, but it’s the right thing to do” gets me every time. I mean how could you not after it’s put to you that way! A true master you are - and we all likely wish there was a you near us! Thanks always for all that you do!

[@active16bits]

This video is what led me to being a rider. I've probably watched this entire thing 20 times. Thank you so much!

[@gmandas]

Rebuilt another pair of carbs. This time on my R 80 RT. Watched the video step-by-step. You are the mentor looking over my shoulder

[@greekspeedfreak]

Great job as always William! Once again, the first time I am venturing into new territory does not seem so terrifying after watching you do it!

[@lasthaxor]

These Boxer 2 Valve videos have been the greatest help while restoring my R90/6. I could not have done without them. Only one thing would make them better...if he would drink beer while doing them. HAHAHA These videos are so RELAXING!!! I love watching over and over.

[@boxer2valve]

That only happens off camera!!

[@kingplumber]

Man do I love these videos, I have loved these bikes since the early 70's. This is like " How it's made" but with way more details.

[@rayparks8805]

I am restoring a 1974 R60/6 and ALL your videos are great, very helpful, very informative, love how detailed every aspect is. I would love to see a video on drum brake maintenance and or repairs. Keep up the great work, thanks.

[@craigsaunders8668]

The time spent and the details have been incredibly useful. I thank you sir

[@mgirano5822]

Merci et félicitations pour ce travail de qualité, bonjour de France.

[@eddiec4081]

Thank you very much for putting these video series together. It’s like having a tutor next to you. You are so thorough that yo make me think of all the right parts to consider getting while doing the rebuild and not only what I think. Thanks for that.

[@markepler96]

Thank you for this fantastically thorough, understandable, quality tutorial. This gave me the confidence to tackle this rebuild myself and I'm looking forward to getting the carbs back on the bike and me back on the road!

[@boxer2valve]

Great to hear. Thanks for watching.

[@melroset-top9139]

Wow, thank you! Makes the upcoming rebuild a little less daunting. I'll be back like 50 more times to re-watch

[@lastairhead]

wow! this is so nice to have all the components explained! Thank you! I am really looking forward to witness these carbs in sync.

[@boxer2valve]

We are very happy that we have been able to help.

[@notinthehead]

Great high quality tutorial! I'm maintaining my 1980 R65 and this has helped me tremendously! Great series you put together!

[@gregorysukroo2197]

I wish you were my R75-5 mechanic. Such a great way that you explain the whole process. Thanks for taking so much of your time to help those who now think they can follow your good advice and expertise.

[@larrygraham2795]

My project bike is a 74 R90/6. These videos are an incredible resource. Ordered some parts today. Thank you. LG

[@boxer2valve]

Hi Larry, thanks for the kind comments and your business. Have fun with your project!

[@JeffWerner]

Great tip (@25:40) about the choke gasket sealer-I'd just pulled my Bings apart and assumed the PO had screwed up the installation last time it was apart. Now realize it can get sucked in.

[@boxer2valve]

Hi Jeff, thanks. I'm glad that we were able to help.

[@matteopanzani5952]

Thank you very much for all your incredible and precious video ! You are the best “Motorrad “mechanic in the World !

[@daveberquist2593]

William - can I buy you dinner the next time I'm in town? You have saved me so much time and frustration. I owe you, big time!

[@robertboffa6187]

Thank you William and boxer2valve for all of your excellent videos. Great work all around.

[@boxer2valve]

Thank you kindly

[@markguppy2715]

A very helpful tutorial, thank you.

[@papatayloreaton]

Thanks guys for all the help yous have done great job for my r80rt

[@placidocentrino3626]

William, this video is great and it made it possible for me to successfully rebuild my carbs. One thing: there was no guidance on orienting the diaphragms, which have nubs that mate up with pockets on the slider and carb body. I checked the Clymer manual because I wasn’t sure about slider orientation , and the manual says it’s important to align the nubs/pockets. That gets the slider in the right orientation and avoids leaving a pocket infilled, which could allow a leak. Anyway, I consider your videos a very generous gift to the future, as long as we can keep burning gas!

[@paulhenderson2142]

You are a god among mere mortals! I rebuilt the carbs on my '87 R80 using this video, and it worked out very well. The production quality is way better than what we typically see on the Tube. By the way, the blue overalls make you look like the guys on the factory floor in Berlin where they build the motorcycles. ;-)

[@amedeeaucoin7380]

I have a '74 R90S and I really like these videos. I have moderate wrenching abilities and these videos give really good information and tips. BMW2valve also are a good source of parts and tools. I've just ordered some Everbest petcocks with a friends ordere who was getting parts for a clutch / main seal job. The host's explanations are spot on.

[@raymondmartinezjr7718]

Great video. I’m rebuilding my carbs for my 83 R100RT. I missed that y’all had rebuild kits for 40mm carbs.

[@simoncrowe3002]

Awesome video. I'll do my carbs this winter - 1976 R90/6. Wish me luck 😧🤞

[@CurtisSound]

Great tip for the float adjustment. I'll try that one next time.

[@jacklinden780]

Great quality, both the explanations and the video.

[@simoncrooks7441]

Thanks, good presentation

[@hotchihuahua1546]

I’ve found using a small spring loaded center punch works well to remove the float pin !

[@boxer2valve]

Thanks for the tip !

[@gustavekeraressi9224]

sir you're the best master thank you so much

[@felixmohren4831]

Fantastic video! Thank you very much.

[@boxer2valve]

Glad you liked it!

[@alanhoughton3252]

Excellent tutorial, do you have a video of tuning and setting up the carbs please!

[@STEVEBLACKA]

Fantastic video . Thanks 🙏

[@cryptoallmight]

Your videos are godsend!

[@jamieharmon3108]

Thanks for this - I ordered the kit and will do this job next weekend

[@boxer2valve]

Have fun!

[@jeffchapman3912]

Thanks so much, great video!

[@malcolmnash5850]

Thank you very much because I'm going to try and do this very job myself , very informative Tutorial once again.

[@boxer2valve]

Glad it was helpful!

[@DavidAllen-wj3iu]

Excellent. I just need to go back and start again.

[@6CylSuccessVideos]

Another great video! Thank you!

[@davebramsen100]

Thank you. 2 things: (1) I find it a PAIN in this SIMPLEST task of putting the tiniest o-ring on the outside mixture screw - worrying about overstretching it or not damaging the needle on the screw ….?! (2) Last step: You should stick your finger in the carb throat and lift the CV slide and make sure it descends smoothly on its own. I just got a couple diaphragms from one of the major aftermarket guys (generally good) and the diaphragms were of rubber that was slightly too heavy, and the slide would not descend! (Also, the outside diameter of the diaphragm was very slightly larger than it should be and didn’t drop readily into the recess like OEM does. )

[@DieterHoremans777]

i have a R100/7 with the same carbs and thought there should be a spring above the diaphragm, i installed some and might test it tomorrow.

[@coreyknapp2151]

Thanks for the video. I am working on a R90/6 and the left carb leaks and the right is running rich. I now understand how to rebuild them.

[@azhirise]

You make it look so easy :-) thanks again.

[@boxer2valve]

Hi Gerald! You're welcome. It's as easy as it looks!

[@BarwickGreen]

Very clear and helpful thankyou

[@boxer2valve]

Glad it was helpful!

[@NChirikos]

I am learning about carb adjustments & balancing on my '81 R80 G/S. Thanks much for the excellent video! I have rebuilt my carbs once and they are working fine except for a developing high idle at running temperature. I noticed William's application of Gasket sealer at the enrichener cover gasket which may be a culprit. I also read Snowbum's excellent coverage of this issue. He mentions that the cover screws are "notorious" for loosening and may cause the gasket to suck inwards causing a vacuum leak. Can you address and perhaps reconcile the different approaches to this problem?

[@brianhoover6990]

I also would love to see some videos for /2. Like timing and carb synch. Thanks so much.

[@boxer2valve]

We're just getting the shop caught up after our move from CA to NC. Stay tuned for future videos. We have a /2 that we can hopefully do a video in the future.

[@coreyknapp2151]

Great video. Thanks for the help. Don’t think i could have done it by myself.

[@davewilliams9307]

Very well done thanks.

[@boxer2valve]

Thank you too!

[@barrynix6346]

Thanks for another great video. Cheers

[@boxer2valve]

You're welcome. Thank you!

[@ChrisHill-vr7tg]

Video was awesome I would have never caught the mark on the choke.

[@johnarisman2022]

Absolutely great videos. So glad you are doing this for us airheads. Any plans to produce a DVD with all the episodes when you're done with the project?

[@boxer2valve]

Hello John. We really had not thought about that but we'll certainly give it some consideration if there is a demand. The videos will however remain on KZbin indefinitely. Thanks for the idea.

[@jeffshootsstuff]

Great video, thanks. If I'm rebuilding an R90/6 that has sat for 20 years but the carbs were drained before it was parked, do you think I'll still need to replace all the O-rings and gaskets in the carbs?

[@Philjjz]

Great video, well presented, thanks. About to do my Bings on my R65, so a great help. I just wondered about a spot of lube on the butterfly shaft, would that be a bad idea?

[@boxer2valve]

Not a bad idea at all! However, lubricants can also attract dirt, so a light lube if at all (like WD40).

[@jamesgault7383]

I noticed the small dome at the very top of the carb look very much improved at the end of the video, how did you make it look so much better, please?

[@jirvin4505]

Yes that would be useful info..... was wondering the same myself

[@patrkbukly4240]

Great video. Thank you.

[@jirvin4505]

Thanks for a confidence inspiring video

[@boxer2valve]

So nice of you

[@joelj1925]

Is there no throttle spring between the top and the piston? I pulled my apart, and they were just like yours, no spring, I thought someone had omitted it by error. I have a 1975 R90/6... with no spring, does the piston work by vacuum? BTY... GREAT series, and really well put together... VERY much appreciated!!

[@kurobisukou123]

very helpful thanks mate

[@boxer2valve]

Any time!

[@FourIntoOne]

Excellent presentation. You didn't talk about checking the correct needle height (you never know what a previous owner may have done) which might be important .........

[@lukaskriz5320]

fantastic,cant wait to restore my ones on R80s

[@hermanboing8489]

Fantastic. I'm on the fence about a 75' R 75/6 right now. It seems to be in great shape and the guy selling it (local) will hook me up with a network. I'm a bit intimidated by the upkeep though. These bikes are a world in themselves.

[@boxer2valve]

It's not everyone's thing. Mostly work is needed because of neglect. Once you have it all sorted out, they are reliable and fun machines.

[@user-gl2eq2ly4g]

Excellent ....very thorough...thank you

[@honzasgarage5125]

Did I miss that or are you not using a float needle clip?

[@charlijoe7280]

Thanks so much for your investment into providing good content. I have a '78 r100/7 with a Siebenrock head/piston kit (that I see you have advertised). My bike has been sitting a couple years, stored at my pop's. I delivered it empty carb'd, but I believe my dad was well-meaning and ran the bike a year ago, leaving shit fuel to varnish up my carbs. I went through burining out my old starter and another new starter from Amazon while trying to start what was once a perfectly running bike. I've never had the time to get to know my carbs, but now I feel totally confident to service them after watching your vid... as though I am driving to a house I have already visited. My bike was blowing a little black smoke and coughing. I found a fouled plug. Would you say that cleaning my carbs, new plugs, and fresh fuel will do the trick? Thanks again!

[@boxer2valve]

Hi, it's important that you have all of the basics right. That means set the valve clearances, make sure the ignition timing is correct and then you can suspect the carburetors. There are many variables so it's not certain that cleaning the carbs and new fuel & plus is all that is needed.

[@charlijoe7280]

@@boxer2valve Thanks for the tips. I can't be positive of course, but the valves were adjusted 1,500 miles, so I'm guessing and hoping they are still OK. The ignition is electronic on this bike, so I'm good there. I will be checking the carbs in a couple days and report back.

[@axlathi]

Another awesome video!! Really appreciate the thoroughness, that you make a point of showing and explaining every step. Great!! BTW: You don't have a problem shipping to Europe right? I could get stuff from Germany but I'd rather get it from you.

[@boxer2valve]

Glad it was helpful! We can ship to Germany! Kein Thema!

[@AndrewTheCelt]

Just a question, I bought my parts from your store and they are awesome but It has as part of the kit, two small red fiber washers and I’m not sure if they are needed with these 40’s but watching the video I don’t see them used. Thank you for your videos and great parts.

[@boxer2valve]

Hi Andrew, The fiber washers are for the vacuum port screws located on the bottom, jest beside the fuel mixture screw. Maybe your bike has rubber vacuum tubes going to those. If so, you won't need those gaskets unless you install the screws which we offer on www.boxer2valve.com under part number 1311869

[@jettaylor1286]

Do you have any thoughts on using an ultrasonic cleaner for cleaning the carb body and parts? I have a small one that could probably fit both bodies.

[@vespasandengines]

With the idle mixture screw... do you screw in to lean the mixture, and screw out to richen?

[@cw284]

If you tear down both carburetor at the same time is there a chance that the diaphragm could be installed in the wrong carburetor ( left or right)and which way do the slides go in in reference to the air filter

[@aarnea]

Needle in the slide. What is too much movement? I think in my slide the hole for the needle is worn out too big. Can it be fixed?

[@DARisse-ji1yw]

But... if the needles need replacement, how do you remove the old & replace ???

[@boxer2valve]

In the center of the slide, there is a screw and once removed, you can turn the needle a quarter turn to remove or adjust position.

[@robertotto3983]

No slide spring on the 32MM????

[@jbparkerma]

William. I love your style. But I'm curious - you didn't clean up or polish the float valve seat. I'm wondering if you've ever adjusted the float tab and had the valve not seal? (ok, I use a mityvac now to check, before I put the Bing back on the bike. but only because I've had large puddles of gas on my bike table, and many swear words followed). Just curious. Some folks spin a q-tip with brass polish or lapping compound. I tried it - it worked well.

[@terryclair2914]

A lot of great tips in the video!!!

[@boxer2valve]

Hi Terry, so glad that you could extract some useful information! Thanks!

[@mattrice3366]

Any chance you will do a /2 series?

[@boxer2valve]

Hi, there is a chance, but no plans anytime soon. We do have an R51/3 on the to-do list, but a few other projects first.

[@mattrice3366]

boxer2valve BMW Restoration and Parts Supplier I hope you do, I have a 65 R50/2 and would love to watch a series on the /2. Thanks for sharing your knowledge, you are upping the KZbin game with your quality vids.

[@NChirikos]

Just watched this again and noticed there was no spring under the cap. Was this spring added in later versions of the 32mm carb?

[@boxer2valve]

The springs can be added and they help to return the slide back down. There are two tensions available and these can be retrofitted if they were not originally installed.

[@noddyandbigears107]

Now I got it... Mag Wheel Cleaner for the small parts. ; ))

[@Krikstar123]

Pure gold!

[@boxer2valve]

Thanks! Glad you liked it!

[@ragazzi25]

When air screw mixture is removed off a R50/5 carb, should gas flow out of its lodging or it is a sign of flooding??? I have that issue with the right carb and it does that from time to time, left side is fine and no gas comes out when air screw is out. Feedback welcome!

[@nickramsey2743]

Hi. One of the screws holding the butterfly in won’t come out. It looks as if the end of the thread is damaged and preventing it from coming through. Do you have any advice in removing it ?

[@pnmacdonald]

Nick Ramsey if you watch the video, he describes exactly how to accomplish that.

[@kingofpaint4676]

I recently bought a R/ 60 at the auction a few days ago, I was able to drain the gas through the petcock on the tank, how do you drain the gas out of the carburetors, is there a way to do that for winterization?

[@minimoe2008]

Would the mixture screw 3 half turns apply for a 64/26/201&202?

[@stancilcampbell4719]

Did not mention setting position of the needle before installing top of carb.

[@foesfly3047]

I wondered about that too. If I remember correctly, there are 2 or 3 grooves in the needle that allow change of insertion depth with a circlip. Advice on how to determine which might be optimal would be excellent. Maybe if operating at higher elevations or closer to sea level could be a factor or if you wish to add or subtract fuel mixture to adjust EGT...

[@jacintyre]

Hi! Thank you for producing this tutorial, it really helped my rebuild. An issue I've had however- putting it all back together is that the left head is running significantly hotter than the right (tested with an IR gun) I realised this is likely because I can't get them to sync as my right side carb mixture screw adjustments are having little to no effect (nothing happens when I close it or open it right up), any ideas where I may have gone wrong or what might be causing it? Cheers!

[@boxer2valve]

Hi, hot usually means lean in this case. Double check your work on the carburetors. There are some very tiny passages that must be free. If not, fuel flow can be blocked casing a lean condition.

[@azhirise]

Having not yet worked on my garage find airhead yet, would it be easier just to remove the engine to do all this work? Are there any advantages to having the engine in the frame or removed on a stand or bench? I will probably be doing all of the same work on mine as you are doing on yours. All this is very informative and extremely helpful.

[@boxer2valve]

Hi Gerald! In my opinion, it's not necessarily easier to remove the motor for the work that we are doing on this bike because the frame actually makes a great support for the motor. It really depends on the scope of work that you are trying to perform and also the equipment that you have available. If it's your intention to completely disassemble the motor, and you have a suitable motor stand available, then removing the motor makes sense. Otherwise all basic repairs and sealing can be done with the motor block in the frame. Doing many of the tasks on a work bench without proper support for the motor can actually make it more difficult. I hope this helps. If not please let me know!

[@roymichaeldeanable]

I always replace the screws on my old bikes carburettor etc when doing a refurb...the metal naturally deteriorates over time.....

[@minimoe2008]

Is there any difference between the 32 MM and 28MM carbs? I have 28's that need to be rebuilt but not sure if the kits match. Needle, jet, items like those.

[@6CylSuccessVideos]

Wish I had this info when I redid the Bings on my 90/6! Great video! Any plans to do one for the Dell’orto ‘s on the R90S? Also, do you carry parts for Dell’orto ‘s? Thanks again for another brilliant piece. You are demystifying the heck out of these bikes for us mere mortals!

[@boxer2valve]

Hi Frank, we are happy that this information is useful. At the moment, we have no plans to do anything similar for the Dell'orto carbs but if an R90S winds up in our possession, that could sure change!

[@britironfreak]

Frank, do a search on Dell Orto and Moto Guzzi and you will find some great rebuild videos. They are not that different to rebuild.

[@symoonstar23]

Mr valve, do you supply cab kits & parts for r80. 1987. Thnks

[@boxer2valve]

Hi, yes we have pretty much all of the parts that you might need for your 87 R80. Please visit our web site. www.boxer2valve.com

[@TRISTANorTRIS]

How would you deal with removing a seized main jet carrier?

[@boxer2valve]

Hi, That can be a big problem. The first thing that I can suggest you try is to disassemble the carburetor as much as possible. Then place it in a pot of water and bring nearly to a boil to heat it evenly. Carefully remove it and immediately try to loosen the part. Of course it will be hot, so take appropriate precautions! If that doesn't work, then you may need to drill it out. This must be done in a good drill press or mill. The size is 12mm so if you can drill out to about 10.5mm then you may be able to cave in the remaining ring and remove it. You will probably need to chase the threads if this is successful and for that you'll need a tap, preferably a bottoming tap and the size should be 12x1.0 Hopefully the hot water trick works for you!

[@dogshome7110]

Just to add: The steel cap in the lid can loosen up and give an air leak. You will see black gunk where it frets the aluminium. It is pressed in with round gaskets and meant never to come out. The aluminium is pressed down onto it from the outside. I pressed mine out from the inside, fettled the (un-pressed) aluminium lip with a dremel and then epoxied the cap back in. This worked fine (is permanent) but can be seen from the outside. If I were doing it a second time, I would probably soak the cap area with acetone to dry it right out and then simply massage some epoxy in from the inside around the edge. This way it would be un-noticeable. Clear laminating epoxy would be best as it clear and very thin.

[@boxer2valve]

Great tip! thanks for contributing that!

[@robertfindlay2325]

This is a very good and very valuable video about renovating an unnecessarily complicated carburettor fitted to a simple twin cylinder motorcycle. The whole fuel set-up on the BMW twin is badly designed for the comfort of the home mechanic. The position of the fuel entry to the carburettor demands that the carburettor has to be fitted to the bike so that the screws for adjustment of idle and cables are not in the best place to work on when tuning the bike. The left carburettor would be better on the right hand side and vice versa; this could have been achieved had the fuel feed come into the bottom of the float chamber rather than the side (as per AMAL Concentric). As for fitting the fuel feed hose, the air hose and the carburettor to the bike, again not home-mechanic friendly. Simplicity is the key and a bit of thought in design by BMW would have improved things for what is basically a very simple job. The flared screws holding the top of the carburettor can be a menace to remove if there is a little bit of corrosion under the flared head of the screw or in the overly fine 5mm metric thread; cheese-headed screws with a coarser thread would have been better. It took me over an hour per carburettor involving extremely careful heating, using a MAP gas torch, of the area of the carburettor holding the screws, repeated drops of kerosine to try to lubricate the thread and use of a 4 ounce hammer to tap down on the screw and shock it as well as tapping the side of the carburettor to again shock the screws' threads into parting company with the carburettor. Then I had to hold the carburettor in a vice and use considerable effort that almost wrecked the Phillips heads of the screws to get the screws loose. When replacing these screws, grease them first. On my Bings the plate carrying the name BING is a rivetted plastic plate, which is a damn silly idea if that plate covers any holes that pass petrol; plastic ages and warps. Give me AMAL Monobloc, Mikuni or Del'orto carbies any day.

[@DARisse-ji1yw]

Wow. I find that, while working on my Bings, light classical music & a small snifter of fine bourbon helps... following this video step by step helps too. Bear in mind that these carbs are not specific to BMW motorcycles. They are also found in aircraft.... so maybe a tad overengineered for a motorcycle... but in aircraft, reliability takes precedent over ease of service. ... a tiny bit of copper anti seize on the cap screws, and maybe the diaphram screws reduces cussing in the future.... Enjoy.

[@USSEntrprise]

man, he sounds just like brian shaw the strongman.

[@flobeeonekinobee2353]

I hate these carbs they're always pissing fuel on my boots, why can't they have decent overflow pipes