54. Honda CX500 Cafe Racer - Keihin Caburetor rebuild

Prelude No. 1 by Chris Zabriskie is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
Source: chriszabriskie.com/preludes/
Artist: chriszabriskie.com/
Honda CX500 Cafe Racer: In this video I have cleaned and prepared the unique V twin engine in this Honda CX500 Cafe racer project so I can start the rebuilding process. A comprehensive approach to cleaning then rebuilding the Keihin carbs with the help of Larry Cargill's book. Checking all specifications, tolerances, oil clearances for excessive wear, before starting rebuild . I will be checking pistons, rings, oil bearings, crank shaft, con rod big end bearings, crank shaft bearings, cam shaft, rockers, rocker shafts, oil pump, clutch, gearbox, and every other part to check against specifications in the factory service manual (FSM). I will be replacing all bearings, oil seal, o rings....you name it, I'll be checking and replacing as required. Please continue to watch as I rebuild this 1982 Honda CX500 engine, documenting the whole process in great detail, and discuss what I plan to do to convert the Honda CX500 form a stock bike to a cafe racer, with a GSXR front end fork conversion and full engine rebuild, spoke wheels, as well as other modifications. This will be a very detailed video series that will show how the Honda CX500 is dismantled then reassembled, and all mechanical aspects of dismantling and rebuilding the Honda CX500 engine will be detailed and documented. I aim to do things like key relocation under seat, relocation of the battery, removal of the air box and rebuilding of the carburetors to include velocity stacks, removal of the H box and replace with straight through exhaust pipes, fitting Motogadget components like the M-Unit Blue, Motogadget Mini, instruments, and a whole range of other mods.The end result should be a unique Honda CX500 Cafe Racer.

[@TheOdontologist]

So I was going to publish this one a bit later, but I liked it a lot so here it is early and out of sequence. So what ey?

[@LRCXed]

This is a great video. It made me smile watching you follow along with the book step by step. Well done! If you don't mind, I'll be sending this video link to folks that have questions while working on they're carbs. Thank you for mentioning me and my book. I'm honored!

[@TheOdontologist]

Not at all. Credit to you for providing an excellent resource. And for those that don't know, Larry wrote the book. A must.😁

[@kevinmartin3244]

Great video, one of your best. You nailed it as they say. What more can I say, keep em coming. I see even Larry is proud of your work!

[@rexmericle5068]

I got Larry's book years ago to do my CX650C carbs. She's been on the road for 6 years now and I haven't touched the carbs once!

[@fernandotrinidad9434]

I needed tho see this. I have a gl400. It’s the Asian version of the gl500. Same carbs with smaller jettings. Thanks for posting this.

[@TheOdontologist]

Cool.

[@scottjefferson3636]

Hey there. I finally got the cx500 to idle right. Someone before I owned opened the right carb some, After I re synced everything, it idled perfect. It was not internal. Thanks. Now I want to mod the swing arm for next size up tire

[@scottjefferson3636]

I didn't totally unhook throttle cable but all the carb stuff goes all the way to lowest position. Guess it's worth a try. 4000 rpms would seem a lot open.

[@carlosgooglemaps94]

Cool!

[@Herolives1]

What year is your cx? my is 81, do they have same carburetor as your? I couldn't find any accurate information regarding mine. Do you have a link to Larry service manual?

[@TheOzzyRaptor1]

Your videos have been a becon of hope while I try and figure out my rebuild on the cx500. I’m a little lost at the moment, finished the tearing it down, engine off and have tones of ideas. Just one thing at a time I guess. Can I ask what book/ sources you were using in the carb rebuild I plan of rebuilding mine as well

[@TheOdontologist]

Thanks Ozzy. motovillage.org/wiki/hondacxgl/index.php?title=Carb_Cleaning_by_Larry

[@bronxnewbie]

Hello!! I love the video!! Amazing stuff before and after!! Can you explain the process (the chemicals and ratio?) to soften the rubber bit between the carb and the cylinder air intake?? My rubbers are harder than steel and makes it so difficult to remove. Thank you!!

[@aorakiboydog]

bronxnewbie same same

[@TheOdontologist]

Oil of wintergreen and Xylene 50:50, soaked for a few days. They will go hard again. Keep it in glass jar and reuse it also. A hot air gun will also do it.

[@davidlong9495]

Any one know where i can obtain a copy Larrys Guide to rebuilding ??

[@jasontaylor3318]

Awesome video!! I'm in the process of rebuilding my carbs for my GL500 and I'm missing the vacuum needle seat on one side. Do you happen to know where to find this part? I'm referring to the part you removed at 5min 19sec. Any help would be appreciated!

[@TheOdontologist]

Second hand only I would guess. Lots of spares available through members of cx500forum.com

[@Flashdogger]

Quick question. On the introductory picture there is jets a jet needle an idle air screw an emulation tube and a cirletrical double sided tube looking thing. What is the name of that double sided tube looking thing ? What does it do? And most important, where does it go? I ask because I have just one extra part. That part. Thanks.

[@TheOdontologist]

If it's the small silver tube you're referring to, it may be the slide jet needle. Look at around the 13:30 mark and slow video down in settings.

[@Herolives1]

I have 81 cx500 custom, do they use the same carburetor? Can you post a link to the rebuild kit, all the cleaners and solvents you use?

[@TheOdontologist]

Hey Jayden. Carbs changed a little between models, but essentially all custom, deluxe, standard and shadow are interchangeable. WD40 to losen stubborn screws and jets, simple green, brushes and fine steel wool for cleaning, ultrasonic cleaner, and Larry Cargill's book to get it right. Nothing else.

[@MohammadTahaKhan]

Thanks for putting the effort into making this video I had a quick question. I've got a 1980 cx500 and am rebuilding my carbs. When you're bench balancing the carbs, and adjusting the butterfly valves, are they closed all the way down of do you leave some air gab? Also, I'm trying to find Larry's book to buy online and am unable to find it. Do you have any ideas? Thanks!

[@TheOdontologist]

Larry's book can be purchased here: www.donlhamon.com/carbbook.html Butterflies are closed so that half the little hole on the bottom is covered, and same on both carbs. That's a good starting point for balancing.

[@MohammadTahaKhan]

@@TheOdontologist Thanks much! I'm waiting on my ultrasonic cleaner, so should have it running this week!

[@jeepingneatus]

I love all the dental tools.

[@TheOdontologist]

Haha....good for something after I retire.

[@rikardbjork3491]

nice video. My jets there is no numbers on them ;)

[@podgysnapper5830]

I find 0:07 your videos, very informative and helpful but I do have one question for you, as I am also in the process of rebuilding my carburetors. Like you I would also like to do away with the original screws and fit Allen bolts can you remember what sizes you used please. Happy new year

[@TheOdontologist]

Hi Podgy. You can get screw sets on ebay for about $50 AUD including shipping, but this link will give you a link to the sizes. Use antiseize if getting stainless screws to prevent galling. Cheers. www.cx500forum.com/threads/screw-size-list-for-carbs.15052/

[@jdwhite2dw]

So where does the aluminium threaded plug go with the slot for a flat tip screwdriver go?

[@TheOdontologist]

15:38 But the answer really is....where you took it out from.

[@jdwhite2dw]

I have that in my rebuild kit also. Just don't see where they go.

[@shivsivaram9872]

Where can I buy the Larry's book?, Thanks

[@scottjefferson3636]

I need mine rebuilt. I just cleaned them and installed the ignitech cdi ignition unit and now it idles at 4,000 rpm's. Not sure why. Im doing this now which is December 27, 2019.

[@TheOdontologist]

Not sure, but have you tried adjusting the idle screw...black knob under carbs.

[@scottjefferson3636]

@@TheOdontologist Yep. Everything is down. Guess they need all new o rings. Chokes work, checked everything twice. It didn't do this before ignitech and carbs cleaned. It's in the carbs though. I didn't use rubber safe carb cleaner.

[@TheOdontologist]

Try unhooking throttle cables from carb. Maybe stuck in open position. Also check throttle mechanism in carb rotates freely and buttrfly valves close all the way. Dont think its internal.

[@scottjefferson3636]

The right side one is open just a little bit. Should they both close all the way together? How would it stay running with both shut all the way? And how would any fuel at all get by?

[@76bombastic]

Commenti Aggiungi un commento... 76bombastic 1 secondo fa Ciao molto interessante il tuo video. Io ho una cx 650E del 1984 i carburatori sono quasi identici. Ho un problema credo sull'aspirazione della benzina, ho fatto una pulizia quasi come la tua cioè non ho separato i due carb. Ma per il resto è tutto pulitissimo. Ho montato il tutto 1 non ricordo dove va posizionato il tubicino quello piccolo che va dal rubinetto del serbatoio al carb(visto che dal rubinetto ci sono 2uscite piccole, quali delle due va collegato al carb. E dove? Poi la regolazione delle due viti che sono fuori dalle vaschette ho contato ad entrambe 3 giri esatti li devo rimettere a 3 giri o devo cambiare? Ho provato a mettere in moto con il serbatoio collegato e la moto non partiva al che mi è sorto un dubbio.... Vuoi vedere che non aspira la benzina? Ovviamente il rubinetto del serbatoio se lo apri senza i tubi come lo giri giri non esce nemmeno una goccia di benzina se non aspiri dal tubicino piccolo l'aria. Quindi con una siringa con un tubicino ho iniettato benzina nel carburatore mediante l'ingresso dove va posizionato il tubicino grande del sebatoio e a quel punto la moto è subito partita: Secondo te cosa è che non va quale possa essere l'inghippo? Se vuoi ti invio un video dimmi pure dove posso inviartelo giusto per capirci meglio. Grazie ancora e spero di risentirti presto ciao

[@TheOdontologist]

Il tubicino è un tubo a vuoto per il carburatore. Quando il motore gira si forma un vuoto che aiuta ad aspirare la benzina dal serbatoio. Non è necessario collegarlo al carburatore. Il tubo più grande va all'aspirazione sul lato del carburatore sinistro. Le viti del minimo risultano 3 giri è una media. Questo è generalmente OK, ma la messa a punto dei carburatori è la cosa migliore. Lo mostro in uno dei miei video. Questo è tradotto con Google, quindi spero che abbia senso.

[@robertwhite9013]

super video bud, just what I'm looking for. where did you get the jets from having trouble finding 120 90 jets? was it the hole rebuild kit you purchased or just the jest? iv read on the forums there bit of a pig to tune up? as iv got pod filters an 2in to1 exhaust now! any tips be appreciated.

[@vals5008]

Hey Robert, i've had some hard times tuning those carbs for my cx 500 myself. I have pod filters and "open" mufflers whit the stock H middle manifold. I've tried different jets but what works for me is the stock fuel jets (78-112) whit a 0.5mm spacer on the needle, mixture is on 2 3/4 turns. It's an easy fix you don't need to remove the carbs, maybe it works for you too.

[@robertwhite9013]

Thanks for the reply, I'll try the 0.5mm washer on the needle, What you mean with she 2,3,4 turns ? Keep up the videos, an keep safe!.

[@vals5008]

@@robertwhite9013 The mixture screw is located on the bottom, engine side (at 14:34 ).From fully closed you turn back the screw for enrichment of the mixture. Mine is set at almost 3 (2 and 3/4) turns but it may differ from yours. Stock setting is 2.5 turns. Check the spark plugs, brown means the mixture is good, if they are white unscrew the mixture by half a turn, if they are black screw in half a turn, ride the bike for 20-30 min and check again the spark plugs. Repeat until they are dark-brownish color. I keep mine on the rich side so the engine doesn't run too hot, fuck emissions it's just one bike ;) The needle i'm talking about is at 15:45, you go spacer-needle-screw-cap. Btw the video is not mine...have a good one :)

[@robertwhite9013]

@@vals5008 Thanks for that bud, I'll give it a try never done it before so hope for the best, may be more questions over next few days lol👌

[@TheOdontologist]

Hey Robert. I got jets from Wemoto in Australia, also in UK, but should be available other places also. Tuning as follows...Idle screws should be , say, 2.5 turns out on both carbs. This is initial setting. Set idle speed to about 1100 RPM with black knob under carbs. Then balance carbs with vacuum gauges connected to intake runners. Then reset idle speed to 1100. Then, 1 carb at a time, turn idle screw out a little at a time, say 1/8 turn, until you reach highest RPM. If you keep turning but RPM doesn't go any higher, return it to that previous position. Reset the idle speed to 1100. Then do same to other carb, and again reset RPM. If for some reason RPM doesn't go up as you turn out, go back to start position of 2.5 turns, and try turning in (closed). Usually turning out will produce best outcome (slightly rich) which is better for engine that slightly lean (will run too hot). Hope that helps.

[@salessi9495]

I'll tell you this: if I still lived in UK you'd be my dentist.

[@TheOdontologist]

@S Alessi...but I'm in Australia!

[@salessi9495]

@@TheOdontologist lol my mistake. You have a nice Scottish accent 😡

[@TheOdontologist]

@@salessi9495 ...Haha...just like Marcel Marceau. 🤣

[@carlosgooglemaps94]

Exactly!, out of sequence!, so if I don't mistaken you jump seven vid's, come on amigo!!, we'r very impatient!!, cheers!!

[@TheOdontologist]

Still editing. 🤣

[@Cromwell648]

Whats with the awful soundtrack. Has someone died?

[@TheOdontologist]

Was that a comment or just your arse cheek flapping? Is this a smart- arse comment or was yours?