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01-24-2009, 7:40 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 IDLE CIRCUIT VIEW! OK everyone, Here is what I have been working on with the help of Blindstitch. I think this is way overdue in the explanation on how and why the idle circuit works, as well as why they need to be cleaned out so well to work properly. I have done a cutaway for you to see how the inside of the systems work. This is just a sample of the things I'm incorporating into the book. I hope these pictures will help folks understand why it is so important to get the insides of a carburetor so clean, and why it does not run right when it's not. This should help also in the understanding of how it works. First up is a view of the air bleed system and the fuel pickup paths. As well as how they mix with the air to emulsify fuel for proper delivery into the motor. Please note all of the slightly small areas around the emulsion tubes where the air is passed into the center to mix with the fuel. This is a key point in proper running on the system. It's how the air/fuel mixes to an atomized mixture. In case your not sure, the right side is the main jet passage. And the left side is the secondary jet passage that is controlled by the needle in the slide. This second picture shows a very intricate picture of the idle circuit and all the related circuits. Each of them must be clear and functioning properly for one another to work. I want you to notice one thing here. Even though it may seem big in this picture, all these passages that are drilled into the body are very small, and are step drilled. This means that as old fuel and calcium deposits build up, the passages, jets and airways get restricted very quickly. ANY restriction in one or another will effect the function of the entire circuit. As you can see, the .018" hole in the low jet would not take very much to plug it up. Also notice the area around the 3 idle holes at the throttle plate and for the idle mixture screw. Lots of places for junk to build up and plug the circuit in this isn't there. Imagine dried up fuel deposits finally getting loosened up and not dissolved or removed all the way. Those strings of gelled fuel and loosened calcium go straight to the only outlet they have. And it's the holes that you need clear for the engine to run below 5000 RPM or at idle. If that tint area at the needle gets plugged, it is why you can't get the idle needle to make a difference when you screw it all the way in. One of these 3 hole's slightly open, is enough to keep it at an idle. But beyond that, it will suffer due to fuel starvation. One more thing. The air cutoff diaphragm controls the extra air bleed in the center hole. As you let off the throttle all the way, the added vacuum signal from the motor travels up to the top side of the diaphragm through the hole in the cover that holds it in, and pulls it up against the spring. And the brass plunger in the center shuts off that center air bleed. This in turn will cause more fuel to be pulled through the low jet (just like if the other air bleeds were plugged on the other side) and adds extra fuel to the motor at off idle. This is how it keeps the engine from having a lean popping in the exhaust when you let off the throttle after high RPM's. It pulls more gas in due to restricted air flow to the system making the off throttle run rich enough for the fuel in the exhaust pipe not to combust and cause popping. I'm sure I have missed a few points to which some will have questions to. But I hope this helps you understand the insides of your carbs a little better. Thanks Blindstitch for the help in editing these photos. Larry If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

01-24-2009, 7:53 PM Blindstitch2002 Joined on 05-16-2007 Greenfield Wisconsin Posts 5,000 Re: IDLE CIRCUIT VIEW! Larry I was curious what the red in the second picture was from. I know you killed the carbs but they shouldn't bleed that much. 1978 Honda Cx500 Maggot 1979 Honda Cx500 Custom 1980 Cx500 Deluxe Buy HTTA Items Quick Reference Info    Report

01-24-2009, 7:57 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! Some sacrifice is needed for betterment of CX kind every where Blindstitch. Some had to be shed. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

01-24-2009, 8:18 PM the cheese Joined on 11-23-2007 Toccoa,GA Posts 795 Re: IDLE CIRCUIT VIEW! Thank you both for your hard work. I enjoyed seeing that. Makes me want to tear mine back apart. Sad to see a carb die. I'll get over it soon........................thats better. How did you cut into it, band saw? Michael 1981 CX500 Custom Sadly sold 1981 CB650 Custom (It Runs!) Just say no to skin graphs, wear your gear!    Report

01-24-2009, 8:29 PM DavidfromWisconsin Joined on 03-19-2008 Appleton, WI Posts 2,458 Re: IDLE CIRCUIT VIEW! Larry and Don, Excellent photos. Thank you for the photo information. It truly is very informative. I think I may have to tackle my carbs one more time yet, since I now know what I didn't clean properly, so they will idle better. David From Wisconsin ... R80Dave '82 GL500I alias Candy '82 GL500I alias Candy II '00 BMW K1200LT & trailer '81 KZ440 (Wife's learning bike)    Report

01-24-2009, 8:29 PM mildhog Joined on 11-21-2007 Chesapeake, VA Posts 856 Re: IDLE CIRCUIT VIEW! Brilliant!  Well Done.  That is so much better than a diagram.  Thanks for sharing. Arnie in VA 1980 GL1100I Goldwing 1982 GL500I Silverwing 1983 GL650 (The stable is full)    Report

01-24-2009, 9:12 PM Abes_CW Joined on 04-17-2007 saskatoon Posts 3,036 Re: IDLE CIRCUIT VIEW! It's either my eyes or my monitor, but I can't really read the text boxes. If you could clear those up, that'd be awesome. 1983 GL650i Had 4 CX/GL's at one point this year, down to one, next spring is another adventure! age 38 (29 plus tax)    Report

01-24-2009, 9:19 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! It took me a long time to figure out how to make this more visible. I didn't like the drawn diagrams either. Believe it or not, this carb came with my bike when I got it 5 years ago. Fitting it's still doing the job in this fashion. I cut it with a portaband, die grinder and belt sander. What a PITA. But I think worth it in the long run. Can you guys read the captions OK? I'm trying to crop the picture without much luck. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

01-24-2009, 9:20 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! Well that answered that! I'll work on it Abes. Might have to redo the pictures. I'm learning this editing stuff very slowly! Abes, right click on the picture and copy it into paint for now. That will let you see the captions better. We are working on trying to make it more legible and larger. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

01-24-2009, 9:26 PM the cheese Joined on 11-23-2007 Toccoa,GA Posts 795 Re: IDLE CIRCUIT VIEW! Some of the captions I can. Some not. I think the brain is filling in what it wants. However if you save them. You can bring em up as big as you want in another program. Oh and by the way, I'm getting a fuel filter now. I get the point. Michael 1981 CX500 Custom Sadly sold 1981 CB650 Custom (It Runs!) Just say no to skin graphs, wear your gear!    Report

01-24-2009, 9:51 PM Connella08 Joined on 06-01-2007 Mendon,MA Posts 340 Re: IDLE CIRCUIT VIEW! its sad to see you had to sacrifice a carb to show this but DAM that is a nice diagram! thanks Larry! im gonna have to tear mine apart again now also to give mine a thorough cleaning. thanks again!    Report

01-24-2009, 9:56 PM Blindstitch2002 Joined on 05-16-2007 Greenfield Wisconsin Posts 5,000 Re: IDLE CIRCUIT VIEW! 1978 Honda Cx500 Maggot 1979 Honda Cx500 Custom 1980 Cx500 Deluxe Buy HTTA Items Quick Reference Info    Report

01-24-2009, 11:56 PM RustyTec Joined on 08-26-2007 Dallas Tx. Posts 606 Re: IDLE CIRCUIT VIEW! I would be very honored to edit them for you - Just send the originals to me, along with the captions. I can figure out where to place them. I must admit that I use a 31 year old program called PhotoImpact. But it works well.  - I am up to this. Trust me. RustyTec ’81 GL500. Dallas Texas. RustyVape Electronic Cigarettes Local NE Dallas, Texas    Report

01-25-2009, 5:42 AM DaveF Joined on 06-11-2008 Lawrenceville, GA Posts 1,232 Re: IDLE CIRCUIT VIEW! Outstanding work!  I can't wait to see the book.  My Web Site 1982 GL500 1983 GL650    Report

01-25-2009, 11:17 AM Willj Joined on 03-24-2008 Vancouver, B.C Canada Posts 176 Re: IDLE CIRCUIT VIEW! That`s great Larry. I`m looking forward to your book as well. You da man!:)    Report

01-26-2009, 4:11 AM RichNCT Joined on 03-02-2006 Connecticut, USA Posts 3,463 Re: IDLE CIRCUIT VIEW! Great work Larry!  This is a huge contribution to the collective knowledge.  Thanks!!  And thanks for playing a supportive role Stitch. Refueling on The James Bay Road, 2009 Born to be relatively wild (for a grampa x 3) GL650I, CX650E, CX650T    Report

01-26-2009, 8:41 PM nippongreen Joined on 03-16-2006 Ottawa, Canada Posts 587 Re: IDLE CIRCUIT VIEW! Larry and Don, Many thanks for all your hard work and great efforts. Muchly appreciated ;-) 79 CX 500D / 82 GL 500i / 79 CX 500 parts bikes x 2 01 ST1100 Chris's Bikes 84 Honda Shadow VT500/78 Honda 185 Twinstar (ride safe).......SKYPE....(nippongreen).. My D.O.B. 21/04/59    Report

01-27-2009, 6:44 AM Trief Joined on 12-16-2008 PSL Florida Posts 84 Re: IDLE CIRCUIT VIEW! Guys ..This is absolutely AWESOME!! it explains it all... 1982 GL500 SilverWing - 16,000 miles    Report

01-29-2009, 3:03 PM Trief Joined on 12-16-2008 PSL Florida Posts 84 Re: IDLE CIRCUIT VIEW! Larry, In the very first picture the jet on the right has another jet under it.  Is that jet removable?? 1982 GL500 SilverWing - 16,000 miles    Report

01-29-2009, 4:24 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! Yes it is Trief. That's the main circuit emulsion tube that needs a screwdriver ground down to fit in there to get it out. It has to be made very tight to the slot of the emulsion tubes tip or it will roll the slot open and jam it in the threads. Some of them can be very stubborn. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

01-29-2009, 5:30 PM WayneDW Joined on 07-28-2006 Minneapolis Posts 1,655 Re: IDLE CIRCUIT VIEW! incredible! thank you, thank you, thank you. Wayne 1983 GL650 Silverwing Interstate WWW.fossilapostles.com    Report

01-29-2009, 6:30 PM Trief Joined on 12-16-2008 PSL Florida Posts 84 Re: IDLE CIRCUIT VIEW! Well I got 1 out but the other well it is all messed up I was able to easy out it now I need a new one. O well ... I guess I need to get a rebuild kit.  Is the CX & the GL carbs the same? at least as far as the rebuild kits go? 1982 GL500 SilverWing - 16,000 miles    Report

01-30-2009, 7:32 AM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! Trief, Yes the kits will be the same. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

02-07-2009, 2:19 PM Connella08 Joined on 06-01-2007 Mendon,MA Posts 340 Re: IDLE CIRCUIT VIEW! why isnt this a sticky post? i keep having to look for it half way down the list. should be at the top!    Report

02-07-2009, 3:55 PM Blindstitch2002 Joined on 05-16-2007 Greenfield Wisconsin Posts 5,000 Re: IDLE CIRCUIT VIEW! I think it's a sticky post in my list. It's under carb cutaway. http://choppercharles.com/cs/forums/76659/ShowPost.aspx 1978 Honda Cx500 Maggot 1979 Honda Cx500 Custom 1980 Cx500 Deluxe Buy HTTA Items Quick Reference Info    Report

02-07-2009, 5:56 PM Connella08 Joined on 06-01-2007 Mendon,MA Posts 340 Re: IDLE CIRCUIT VIEW! didnt realize you had a list posted...thanks    Report

03-24-2009, 9:49 PM RichD Joined on 08-31-2006 Vallejo, CA Posts 226 Thanks for the lesson Great job! Now I know enough to be really dangerous. Rich DeMartile    Report

10-01-2009, 8:17 PM lucky Joined on 03-06-2009 kingman az age 26 Posts 1,443 Re: Thanks for the lesson weres the pics at??? they up and left 1982 honda cx500c 1979 honda xr185 dirt bike If you can read this thank a TEACHER If you're reading this in ENGLISH thank a SOLDIER http://globalcxglvtwins.hostingdelivered.com/    Report

10-01-2009, 8:46 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: Thanks for the lesson Do you see the pictures from my post in the beginning? Or the ones from blindstitch? Or none of them at all? If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

10-01-2009, 8:51 PM lucky Joined on 03-06-2009 kingman az age 26 Posts 1,443 Re: Thanks for the lesson ok now they show up!!!!! figures the almighty carb god shows up and blam there back 1982 honda cx500c 1979 honda xr185 dirt bike If you can read this thank a TEACHER If you're reading this in ENGLISH thank a SOLDIER http://globalcxglvtwins.hostingdelivered.com/    Report

10-02-2009, 7:56 AM Prairie Dog Joined on 05-06-2009 Winnipeg, Manitoba, Canada Posts 90 Re: Thanks for the lesson DAVEF said: Outstanding work! I can't wait to see the book. I think I'll wait for the movie, myself!! 1982 Honda GL500I Silverwing Interstate (19K km) 50 year old teenager    Report

10-02-2009, 12:58 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: Thanks for the lesson Unfortunately I have come to a stand still on the book until winter time hits. After doing 35 pages of it I realized I wanted to change the format and add a few more details. I sent the book out the way it is now to 2 guys while they did their carbs for the first time. It helped them get great results but they had some suggestions that made sense. Small issues that I take for granted needed to be addressed. It will require a full redoo of most of the book. And because I'm building a new 79 CX500 that will be for sale right now I'm not taking the time to work on the book until that's done. Glad to see the pictures are back. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

10-02-2009, 1:12 PM spanish bandit Joined on 02-12-2009 southern spain Posts 5,010 Re: Thanks for the lesson  LRCXed wrote: Unfortunately I have come to a stand still on the book until winter time hits. After doing 35 pages of it I realized I wanted to change the format and add a few more details. I sent the book out the way it is now to 2 guys while they did their carbs for the first time. It helped them get great results but they had some suggestions that made sense. Small issues that I take for granted needed to be addressed. It will require a full redoo of most of the book. And because I'm building a new 79 CX500 that will be for sale right now I'm not taking the time to work on the book until that's done. Glad to see the pictures are back. larry,after all the work you have done,plus, now the need to perfect your book ...is a few more monthes going to make any difference,nah...keep up the good work,and thanks when i feel the need,i do it,llego,ve 60,s ----------------------------- 2008.1982 honda gli silverwing [uk model ] 2010.1981 honda gli silverwing [uk model ]    Report

10-04-2009, 3:47 PM Joel Joined on 08-13-2009 Grand Rapids, Michigan Posts 621 Re: Thanks for the lesson Great work Larry and Don, Now then how does electricity tie into the carb? For example if I have a poor stator doesn't that affect my carbration? I have poor idle and mid range. After viewing this post I am sure I need to re-clean my carbs again. Also do I remove the needle seat to clean that area of the carb body as well? Finally, I too have one of those jets/screws inside to carb that just keeps spinning and will not come out. Makes me think I need a new jet as well as a carb body. 1971 Yamaha 360 1977 Xr75 1973 Cl350 1980 cx500 custom 1983 gl650i 1969 Norton Commando Fastback 750 project (x2)    Report

10-04-2009, 10:41 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: Thanks for the lesson The idle and mid range issue is usually do to a clogged up set of carbs in the low jets. A bad stator if I'm not mistaken will effect the range above 5000 rpm unless one of the ignition winding for one of the cylinders goes out completely. Do not pull out the needle seat. I only did that in the post to show the small areas where debris can build up. Take the time to do the carbs with all the points being attended to in the cleaning post. HERE It will make a world of difference in the way it runs. What is the VB # on the side of the carb? And is it the right or left carb? I'll see if I have one for you. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

10-05-2009, 3:46 PM ki4 Joined on 08-21-2008 New Port Richy, Fla Posts 239 Re: IDLE CIRCUIT VIEW! Hey there been awhile. Have there been any more progress on getting mid jets?? cx 500 c 81 It's my Ugly and I'll ride it if I want to, ride if I want to, you would ride to if you had an Ugly to.    Report

10-05-2009, 6:32 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! They had some shipped into them from japan but the were all wrong in the length. Their working on it to get it corrected. If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

10-13-2009, 5:57 PM ki4 Joined on 08-21-2008 New Port Richy, Fla Posts 239 Re: IDLE CIRCUIT VIEW! I like the cut out view. Nice work, I have a set of carbs you and the people that you know might be interested in. I also know where there is a complete engin in st pete fla . It also has the frount faring. I think it is a 650. The carbs came off the bike I found. I went thrrew most of the carbs already. Just need the jets gone threw yet. cx 500 c 81 It's my Ugly and I'll ride it if I want to, ride if I want to, you would ride to if you had an Ugly to.    Report

10-13-2009, 7:14 PM MikeCMP Joined on 05-27-2009 Chardon, Ohio Posts 354 Re: IDLE CIRCUIT VIEW! Good info, and awesome cut-away's, those look very challenging to do and leave the small passages untouched. Noticed a small mistake in the first picture, right side caption, vacuum is spelled vucuum. :) Mike 1979 CX500 Custom My first bike and loving it!    Report

10-14-2009, 9:26 AM ki4 Joined on 08-21-2008 New Port Richy, Fla Posts 239 Re: IDLE CIRCUIT VIEW! LRCXcd: If you get a chance, e-mail me. I tried to send you one. It came back. It's about the carbs I have here for the cx I got out of St. Pete Fla. These sit closer together. Otherwise from what I see they look the same as my 80 and 81 carbs. They are in very good condition, inside of them also. Thanks. cx 500 c 81 It's my Ugly and I'll ride it if I want to, ride if I want to, you would ride to if you had an Ugly to.    Report

10-14-2009, 5:13 PM LRCXed Joined on 05-15-2008 Sacramento, California Posts 1,670 Re: IDLE CIRCUIT VIEW! Email sent. Sounds to me like you bought a set of GL500 carbs! If your going to do something, do it right, don't do it half as@*d. 78 CX500 Std, 79 CX500 project, 80 CX500C, 83 GL650I http://globalcxglvtwins.hostingdelivered.com/    Report

10-15-2009, 4:25 PM ki4 Joined on 08-21-2008 New Port Richy, Fla Posts 239 Re: IDLE CIRCUIT VIEW! Yea here on the posts I see the same kikd of bike, gl is right. I saw the bike in the junk yard where i bought the crash bars and the carbs. One of the posts shows the 4 gal tank and crass bars with just the vetter frount faring. The whole engin is still intacked also. The air filter was mounted on the right side where my side cover world be. cx 500 c 81 It's my Ugly and I'll ride it if I want to, ride if I want to, you would ride to if you had an Ugly to.    Report

10-15-2009, 4:33 PM ki4 Joined on 08-21-2008 New Port Richy, Fla Posts 239 Re: IDLE CIRCUIT VIEW! So should I move the parts from my 80 cx set, tubs and pivot rods to make the GL's work? Or can I trade,sell? I just would like to have a second set working well for my bike. Just thinking. cx 500 c 81 It's my Ugly and I'll ride it if I want to, ride if I want to, you would ride to if you had an Ugly to.    Report

03-31-2010, 9:33 PM OLD MAN CX500 Joined on 02-02-2010 Posts 164 Re: IDLE CIRCUIT VIEW! nice work on the pics ,just an thought I GOT a tape 5/16 40 tpi to run down the tub and then screw a bolt in for a pulling ap as a 5/16 bolt extractor from mac is weeks away    Report

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