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techtalk:evo:carb02 [2022/05/02 10:24] ixl2relax [More on Jetting] |
techtalk:evo:carb02 [2024/01/02 21:51] (current) hippysmack |
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| This process will give you a good rigid mount of the carb to the cylinder-heads while maintaining a good alignment of the carb with the manifold, all working together to eliminate those pesky intake air leaks.\\ | This process will give you a good rigid mount of the carb to the cylinder-heads while maintaining a good alignment of the carb with the manifold, all working together to eliminate those pesky intake air leaks.\\ | ||
| - | ((http://xlforum.net/forums/showthread.php?postid=5342857#post5342857)) | + | ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/181911-carb-questions?postid=5342857#post3887561)) |
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| **Check the Slide Diaphragm** - Be sure the slide operates correctly & the diaphragm is not torn or punctured. To do this, remove the air cleaner and reach your finger into the carb throat to the slide - push the slide up and quickly let the slide fall down. You should hear the vacuum sound as the slide returns to the bottom position. | **Check the Slide Diaphragm** - Be sure the slide operates correctly & the diaphragm is not torn or punctured. To do this, remove the air cleaner and reach your finger into the carb throat to the slide - push the slide up and quickly let the slide fall down. You should hear the vacuum sound as the slide returns to the bottom position. | ||
| - | This is from an [[http://xlforum.net/forums/showthread.php?t=30748|XLForum thread]]: chrishajer wrote - CBAS5 and I were talking about what it should sound like, good, and we filmed that one. Then he said "you know, we should show a bad one too" so we did that. I think the [vacuum] sound and the speed that the slide comes down are the two most important things. Those things you can't describe to someone really. I can't anyway. But it's absolutely the best way to verify that the diaphragm is seated properly. | + | This is from an [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/18460-audio-and-video-of-cv-carb-diaphragm-good-and-bad?t=30748|XLForum thread]]: chrishajer wrote - CBAS5 and I were talking about what it should sound like, good, and we filmed that one. Then he said "you know, we should show a bad one too" so we did that. I think the [vacuum] sound and the speed that the slide comes down are the two most important things. Those things you can't describe to someone really. I can't anyway. But it's absolutely the best way to verify that the diaphragm is seated properly. |
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| More info & links here: [[:techtalk:evo:carb02c|SubDoc - Why Not Dynojet Kits?]] | More info & links here: [[:techtalk:evo:carb02c|SubDoc - Why Not Dynojet Kits?]] | ||
| - | **__To check for DynoJet parts, look at these 4 things:__** ((Identify DJ vs Keihin - http://xlforum.net/forums/showpost.php?p=5238545)) | + | **__To check for DynoJet parts, look at these 4 things:__** ((Identify DJ vs Keihin - https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/178513-01-1200c-jets-needle-issue#post3816633)) |
| * Check the Needle: Stock is Nail-shaped - DJ has grooves & a clip | * Check the Needle: Stock is Nail-shaped - DJ has grooves & a clip | ||
| * Check the Diaphragm/Slide Spring: Stock is 6.0" - DJ is 5.75" | * Check the Diaphragm/Slide Spring: Stock is 6.0" - DJ is 5.75" | ||
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| | {{:techtalk:evo:carb:cv40-needle-em-jets.jpg?360| Photo by IXL2Relax at the XLForum}} | {{:techtalk:evo:carb:cv40-needle-jet.jpg?200| Annotated by IXL2Relax at the XLForum}} | {{:techtalk:evo:carb:cv-idlemixscrew.jpg?150|}} \\ **Assemble in Correct Order**\\ Onto IMS Needle pointed up,\\ put the Spring, then Washer,\\ and O-Ring goes on top. | | | {{:techtalk:evo:carb:cv40-needle-em-jets.jpg?360| Photo by IXL2Relax at the XLForum}} | {{:techtalk:evo:carb:cv40-needle-jet.jpg?200| Annotated by IXL2Relax at the XLForum}} | {{:techtalk:evo:carb:cv-idlemixscrew.jpg?150|}} \\ **Assemble in Correct Order**\\ Onto IMS Needle pointed up,\\ put the Spring, then Washer,\\ and O-Ring goes on top. | | ||
| - | From the factory, there is a cap over the Idle Mixture Screw. This needs to be removed to make IMS adjustments during tuning. It does not need to be replaced when done, but the cap is available as HD P/N 28015-01 if you would like to replace it when done making changes.((IMS Cap - http://xlforum.net/forums/showpost.php?p=595622&postcount=9)) | + | From the factory, there is a cap over the Idle Mixture Screw. This needs to be removed to make IMS adjustments during tuning. It does not need to be replaced when done, but the cap is available as HD P/N 28015-01 if you would like to replace it when done making changes.((IMS Cap - https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/27030-carb-jetting-i-can-t-see-this-issue-covered-elsewhere?postcount=9#post612368)) |
| The Idle Mixture Screw "packing" (spring, washer, o-ring) and the screw itself was never meant to be removed or tampered with, according to the MoCo, due to EPA regulations. This was adjusted and the screw covered with a soft aluminum cap at the factory before initial installation on your bike. None of these packing items are offered as replacement parts from your HD dealer, so you will need to look to the aftermarket suppliers for parts. | The Idle Mixture Screw "packing" (spring, washer, o-ring) and the screw itself was never meant to be removed or tampered with, according to the MoCo, due to EPA regulations. This was adjusted and the screw covered with a soft aluminum cap at the factory before initial installation on your bike. None of these packing items are offered as replacement parts from your HD dealer, so you will need to look to the aftermarket suppliers for parts. | ||
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| To remove the IMS cap, carefully drill a small hole in the center of the cap (barely enough to make a hole). Be extremely careful not to overdrill into the cap because you will damage the screw that is behind the cap. Now, carefully twist in a sheetmetal screw about one thread, then pull on the screw to remove the cap. | To remove the IMS cap, carefully drill a small hole in the center of the cap (barely enough to make a hole). Be extremely careful not to overdrill into the cap because you will damage the screw that is behind the cap. Now, carefully twist in a sheetmetal screw about one thread, then pull on the screw to remove the cap. | ||
| - | An aftermarket kit (like E-Z-just) can be purchased with an extended screw head for hand tuning. It comes with the "packing" in case yours has been damaged or is not functioning properly. But, check your local regulations before changing this out to an aftermarket part. You can also find, buy or barter for used parts. ("Please note: it is a violation of federal law to tamper with or disable any emission or noise control device. That is your PSA for the day"((XLForum member - chrishajer)) ((a/f screw packing photo by tchuck of the XLFORUM http://xlforum.net/forums/showthread.php?t=183642)). | + | An aftermarket kit (like E-Z-just) can be purchased with an extended screw head for hand tuning. It comes with the "packing" in case yours has been damaged or is not functioning properly. But, check your local regulations before changing this out to an aftermarket part. You can also find, buy or barter for used parts. ("Please note: it is a violation of federal law to tamper with or disable any emission or noise control device. That is your PSA for the day"((XLForum member - chrishajer)) ((a/f screw packing photo by tchuck of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/47776-idle-mixture-needle-mod?t=183642)). |
| **Checklist Of What You Have** - In order for others to provide quality advice, it is important that you know and can provide quality information about the build of your bike. Here's a list of important information for you to know and provide for TUNING of the CV carburetored EVOs (1986-2006): | **Checklist Of What You Have** - In order for others to provide quality advice, it is important that you know and can provide quality information about the build of your bike. Here's a list of important information for you to know and provide for TUNING of the CV carburetored EVOs (1986-2006): | ||
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| |Fuel Float Valve |(Y/N - Cleaned & Checked, Replaced)| | |Fuel Float Valve |(Y/N - Cleaned & Checked, Replaced)| | ||
| - | | {{ :techtalk:evo:engmech:measure-883-1200.jpg?170|}} **TIP - Do you have an 883 or 1200 size engine?** ((Decman of the XLForum - xlforum.net/forums/showpost.php?p=3171730)) {{:common:space100x5px.jpg?direct&140|}} \\ If you don't know your engine size, check it with a straw - Like this:\\ \\ * Put bike on lift or otherwise raise rear tire\\ * Put transmission in 5th gear\\ * Remove both spark plugs\\ * Place a long plastic straw, chopstick, etc. in the spark plug hole\\ \\ * Rotate tire to move cylinder to bottom dead center - lowest straw position\\ * Measure the cylinder diagonal dimension\\ * Check from far bottom of cylinder to top lip of spark plug hole\\ \\ * If 883 bore then 5.5" Diagonally ---- (Actual Bore Dia. is 3.000)\\ * If 1200 bore then 5.875" Diagonally - (Actual Bore Dia. is 3.498)\\ \\ Straw won't damage the cylinder and unlikely to fall into the cavity.\\ | | + | | {{ :techtalk:evo:engmech:measure-883-1200.jpg?170|}} **TIP - Do you have an 883 or 1200 size engine?** ((Decman of the XLForum - https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/112707-telling-the-difference-between-a-1200-and-an-883#post2368319)) {{:common:space100x5px.jpg?direct&140|}} \\ If you don't know your engine size, check it with a straw - Like this:\\ \\ * Put bike on lift or otherwise raise rear tire\\ * Put transmission in 5th gear\\ * Remove both spark plugs\\ * Place a long plastic straw, chopstick, etc. in the spark plug hole\\ \\ * Rotate tire to move cylinder to bottom dead center - lowest straw position\\ * Measure the cylinder diagonal dimension\\ * Check from far bottom of cylinder to top lip of spark plug hole\\ \\ * If 883 bore then 5.5" Diagonally ---- (Actual Bore Dia. is 3.000)\\ * If 1200 bore then 5.875" Diagonally - (Actual Bore Dia. is 3.498)\\ \\ Straw won't damage the cylinder and unlikely to fall into the cavity.\\ | |
| \\ | \\ | ||
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| {{:techtalk:evo:carb:cv40-floatvalve-02.jpg?300|}}{{:techtalk:evo:carb:cv40-floatvalve-01.jpg?400|}} | {{:techtalk:evo:carb:cv40-floatvalve-02.jpg?300|}}{{:techtalk:evo:carb:cv40-floatvalve-01.jpg?400|}} | ||
| - | In [[http://xlforum.net/forums/showthread.php?t=2074492|This XLForum Thread]] there is a discussion of the float bowl overflowing and the possibility that it is caused by aftermarket float valves that are not of the proper design.((Images above by Hippysmack of the XLForum)) | + | In [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/197805-carb-flooding?t=2074492|This XLForum Thread]] there is a discussion of the float bowl overflowing and the possibility that it is caused by aftermarket float valves that are not of the proper design.((Images above by Hippysmack of the XLForum)) |
| ** Tip for Checking Fuel/Float Level - With Carb Installed ** | ** Tip for Checking Fuel/Float Level - With Carb Installed ** | ||
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| * Check intake seals on manifold (at heads) - replace now while it's apart | * Check intake seals on manifold (at heads) - replace now while it's apart | ||
| * Check intake seal between manifold & carb - replace now | * Check intake seal between manifold & carb - replace now | ||
| - | * Minimize Throttle Plate opening at idle - Set it between Idle Port & Transfer Ports if possible [[http://xlforum.net/forums/showthread.php?t=1635658|(See this XLForum thread)]] | + | * Minimize Throttle Plate opening at idle - Set it between Idle Port & Transfer Ports if possible [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/151434-cv-carb-transfer-ports?t=1635658|(See this XLForum thread)]] |
| * Check Idle Mixture Screw (IMS) screw/spring/washer/o-ring condition - clean port | * Check Idle Mixture Screw (IMS) screw/spring/washer/o-ring condition - clean port | ||
| * Check IMS seat (Has the screw needle tip deformed the hole?) | * Check IMS seat (Has the screw needle tip deformed the hole?) | ||
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| You'll need (4) screws that are 16mm in length for the float bowl. Then you'll need (3) screws that are 16mm in length and (1) screw that is 20mm in length for the Diaphragm Cover. If you choose to use **Button Socket Head** Screws for the top cover, they use a 2.5mm hex wrench. | You'll need (4) screws that are 16mm in length for the float bowl. Then you'll need (3) screws that are 16mm in length and (1) screw that is 20mm in length for the Diaphragm Cover. If you choose to use **Button Socket Head** Screws for the top cover, they use a 2.5mm hex wrench. | ||
| - | You can also replace the (3) Accelerator Pump screws with 4mm x 10mm long. ((rocketmangb & Folkie - http://xlforum.net/forums/showthread.php?t=635308)) | + | You can also replace the (3) Accelerator Pump screws with 4mm x 10mm long. ((rocketmangb & Folkie - https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/84266-cv-carb-screw-kits?t=635308)) |
| Summary List:\\ | Summary List:\\ | ||
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| - | ( Also see: [[http://xlforum.net/vbportal/forums/showthread.php?t=167074|XLF Thread 1]], [[http://xlforum.net/vbportal/forums/showthread.php?t=1966443|XLF Thread 2]] & [[http://xlforum.net/vbportal/forums/showthread.php?t=1792262|XLF Thread 3]], [[http://xlforum.net/vbportal/forums/showthread.php?t=165259|XLF Thread 4]] ) | + | ( Also see: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/46148-stripped-my-float-bowl-screw-head-now-what?t=167074|XLF Thread 1]], [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/182569-carb-float-bowl-screws?t=1966443|XLF Thread 2]] & [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-general-discussion-and-problems/166789-just-bought-a-used-sportster-checklists-for-making-it-right?t=1792262|XLF Thread 3]], [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/46008-cv-needle-drawings-and-database?t=165259|XLF Thread 4]] ) |
| As a reference, here are the OEM parts for the Carb Top Cover: | As a reference, here are the OEM parts for the Carb Top Cover: | ||
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| ==== Reinstall Slide, Diaphragm & Cover ==== | ==== Reinstall Slide, Diaphragm & Cover ==== | ||
| - | To prevent tearing the Slide Diaphragm (reinstalling) - Shu: ((Shu from this XLF thread: http://xlforum.net/forums/showthread.php?t=167074 Post#19))\\ | + | To prevent tearing the Slide Diaphragm (reinstalling) - Shu: ((Shu from this XLF thread: https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/46148-stripped-my-float-bowl-screw-head-now-what?t=167074+Post#19))\\ |
| * Use four small dabs of wheel bearing grease in the seal channel spaced between the screw holes | * Use four small dabs of wheel bearing grease in the seal channel spaced between the screw holes | ||
| * Drop the slide into the carb (with needle, spider & spring in the center) | * Drop the slide into the carb (with needle, spider & spring in the center) | ||
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| **Needle & Needle Jet** - The needle is a tapered, nail-like, rod that operates from the bottom of the slide into the needle jet. It does not affect the flow of fuel until the throttle plate opens sufficiently to create an active vacuum in the outer section of the venturi, which will lift the slide and move the needle in the needle jet. The fuel mix supplied thru the needle jet, by your selected needle and the emulsion tube, will combine with the transfer fuel mix of the slow jet as the carb operation moves out of the transfer period into the mid-range of the throttle/slide function. | **Needle & Needle Jet** - The needle is a tapered, nail-like, rod that operates from the bottom of the slide into the needle jet. It does not affect the flow of fuel until the throttle plate opens sufficiently to create an active vacuum in the outer section of the venturi, which will lift the slide and move the needle in the needle jet. The fuel mix supplied thru the needle jet, by your selected needle and the emulsion tube, will combine with the transfer fuel mix of the slow jet as the carb operation moves out of the transfer period into the mid-range of the throttle/slide function. | ||
| - | The main jet, located at the bottom of the emulsion tube, is way below where the needle rides. It has no variable relationship with what the needle does except to create an eventual upper fuel limit at WOT, when the needle is fully out of the needle jet. ((wedge of the XLFORUM http://xlforum.net/forums/showthread.php?t=1820463&page=9)) The needle rides in the needle jet which is the silver colored jet (hollow cylinder) that sticks up from the bottom of the throat of the carb. The tapered needle moves up and down thru this constant orifice during the vacuum slide operation. | + | The main jet, located at the bottom of the emulsion tube, is way below where the needle rides. It has no variable relationship with what the needle does except to create an eventual upper fuel limit at WOT, when the needle is fully out of the needle jet. ((wedge of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/169629-read-my-plugs/page9?t=1820463&page=9)) The needle rides in the needle jet which is the silver colored jet (hollow cylinder) that sticks up from the bottom of the throat of the carb. The tapered needle moves up and down thru this constant orifice during the vacuum slide operation. |
| The space between the needle and needle jet control fuel flow coming out of the emulsion tube into the throat. After the needle is out of the needle jet, then the main jet will become the limiting factor for the fuel flow at the wide open throttle position (WOT). Until the needle gets out of the way, the main jet is doing nothing to limit the needed fuel. | The space between the needle and needle jet control fuel flow coming out of the emulsion tube into the throat. After the needle is out of the needle jet, then the main jet will become the limiting factor for the fuel flow at the wide open throttle position (WOT). Until the needle gets out of the way, the main jet is doing nothing to limit the needed fuel. | ||
| - | Significant Comment by Don Burton from this detailed discussion of __some of the needle dimensions__ at [[http://xlforum.net/forums/showthread.php?t=165259|this interesting XLForum Thread]]:\\ | + | Significant Comment by Don Burton from this detailed discussion of __some of the needle dimensions__ at [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/46008-cv-needle-drawings-and-database?t=165259|this interesting XLForum Thread]]:\\ |
| "Also, elsewhere someone has measured the inside diameter of the needle jet (the needle jet, not the jet needle) as being just .114 of an inch. If so, that explains why just .001 of an inch difference in diameter of the straight portion of the needle (usually measures between .107-.110, depending upon the needle) makes a significant difference in air/fuel ratio at just above off idle and in the lower throttle settings." | "Also, elsewhere someone has measured the inside diameter of the needle jet (the needle jet, not the jet needle) as being just .114 of an inch. If so, that explains why just .001 of an inch difference in diameter of the straight portion of the needle (usually measures between .107-.110, depending upon the needle) makes a significant difference in air/fuel ratio at just above off idle and in the lower throttle settings." | ||
| - | **Emulsion Tube**((stevo of the XLFORUM http://xlforum.net/forums/showthread.php?t=2876))- As the throttle plate is opened further the main circuit comes into play. Fuel enters the bottom of the emulsion tube thru the main jet. Air enters thru the main air bleed jet in the front of the carb. The air and fuel are mixed in the emulsion tube before this fuel mixture passes up the tube past the needle jet and needle into the carb venturi and down the intake chasing after (combining with) the idle circuit fuel mix. The size, number and position of the holes in the emulsion tube effect the fuel delivery. More holes = more air = leaner mixture. More holes at the top = leaner mixture at low speeds. More holes at the bottom = leaner mixture at high speeds. If you change emulsion tubes you need to use a compatible needle. It will also have an effect on the main jet size (at WOT) and quite often the pilot circuit thru the just-off-idle response. Needles, needle jet, emulsion tube (size, position and amount of holes), main air bleed size and main jet are all closely linked. Changing one can affect the others and all have an affect on the fuel delivery to differing amount at different throttle positions. | + | **Emulsion Tube**((stevo of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/1974-question-about-function-of-the-emulsion-tube?t=2876))- As the throttle plate is opened further the main circuit comes into play. Fuel enters the bottom of the emulsion tube thru the main jet. Air enters thru the main air bleed jet in the front of the carb. The air and fuel are mixed in the emulsion tube before this fuel mixture passes up the tube past the needle jet and needle into the carb venturi and down the intake chasing after (combining with) the idle circuit fuel mix. The size, number and position of the holes in the emulsion tube effect the fuel delivery. More holes = more air = leaner mixture. More holes at the top = leaner mixture at low speeds. More holes at the bottom = leaner mixture at high speeds. If you change emulsion tubes you need to use a compatible needle. It will also have an effect on the main jet size (at WOT) and quite often the pilot circuit thru the just-off-idle response. Needles, needle jet, emulsion tube (size, position and amount of holes), main air bleed size and main jet are all closely linked. Changing one can affect the others and all have an affect on the fuel delivery to differing amount at different throttle positions. |
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| {{ :techtalk:evo:carb:cv40-imscap-drillbit.jpg?200|}} | {{ :techtalk:evo:carb:cv40-imscap-drillbit.jpg?200|}} | ||
| - | **IMS Cap** - From the factory, the cavity for the Idle Mixture Screw (IMS) is covered with a small cap. (Note from the service manual: Adjusting mixture setting by procedures other than those specified in the manual may be in violation of local regulations.) The following procedures are not specified in the manual. To remove the cap and gain access to the IMS, use a small drill bit to create a hole in the cap. Use several layers of tape on the drill bit to limit the depth the bit can penetrate the cap. If you pop thru the cap too deep with the bit, you may damage the internal screw head - Be Careful. Once your cap has a hole in it, CAREFULLY thread a self-tapping screw (blunt nose) into the hole JUST ENOUGH to capture the cap & pull it out of the IMS cavity.((photo by cantolina of the XLFORUM http://xlforum.net/forums/showthread.php?t=14949)) If you want to replace the cap, it is HD P/N 28015-01. | + | **IMS Cap** - From the factory, the cavity for the Idle Mixture Screw (IMS) is covered with a small cap. (Note from the service manual: Adjusting mixture setting by procedures other than those specified in the manual may be in violation of local regulations.) The following procedures are not specified in the manual. To remove the cap and gain access to the IMS, use a small drill bit to create a hole in the cap. Use several layers of tape on the drill bit to limit the depth the bit can penetrate the cap. If you pop thru the cap too deep with the bit, you may damage the internal screw head - Be Careful. Once your cap has a hole in it, CAREFULLY thread a self-tapping screw (blunt nose) into the hole JUST ENOUGH to capture the cap & pull it out of the IMS cavity.((photo by cantolina of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/9621-carb-adjusting-where-are-the-jets-and-the-mixture-screw?t=14949)) If you want to replace the cap, it is HD P/N 28015-01. |
| **Slow Jet, Transfer Ports, Idle Port & Idle Mixture Screw** - As illustrated below, these parts function in a close relationship. The size of the Slow Jet creates a fuel mixture that is delivered to the Transfer Ports (5 openings), but is also flowed to the Idle Mixture Screw (IMS). The IMS is adjusted in small increments to allow some of the fuel mixture (from the Slow Jet) to be flowed thru the Idle Port (one opening). In this way, while both the Idle Port & the Transfer Ports are dependent on the Slow Jet, the amount of fuel to the Idle Port fuel can be controlled separately from the Transfer Ports by using the Idle Mixture Screw. A more detailed description of this operaiton follows this brief overview. | **Slow Jet, Transfer Ports, Idle Port & Idle Mixture Screw** - As illustrated below, these parts function in a close relationship. The size of the Slow Jet creates a fuel mixture that is delivered to the Transfer Ports (5 openings), but is also flowed to the Idle Mixture Screw (IMS). The IMS is adjusted in small increments to allow some of the fuel mixture (from the Slow Jet) to be flowed thru the Idle Port (one opening). In this way, while both the Idle Port & the Transfer Ports are dependent on the Slow Jet, the amount of fuel to the Idle Port fuel can be controlled separately from the Transfer Ports by using the Idle Mixture Screw. A more detailed description of this operaiton follows this brief overview. | ||
| - | **Note:** There is an XLForum discussion thread regarding the relationship between the Transfer Ports and the Slow Jet (AKA Pilot Jet): [[http://xlforum.net/forums/showthread.php?t=1635658 ]] ((Article from XLForum member IXL2Relax)) | + | **Note:** There is an XLForum discussion thread regarding the relationship between the Transfer Ports and the Slow Jet (AKA Pilot Jet): [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/151434-cv-carb-transfer-ports?t=1635658]] ((Article from XLForum member IXL2Relax)) |
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| - | | **Note - Trouble Finding A Change** - You may still have the throttle plate too far open, thereby running on the Transfer Ports instead of the Idle Port. But, if you have carefully set the throttle plate & still can't find a fall off until below 1/2 turn out, you need a smaller Slow Jet. If you can't find a fall off in idle until beyond 3-1/2 turns out, you need a larger Slow Jet. However, it is not recommended to use a smaller size than 42 nor larger size than 46. If the IMS setting appears to make no difference, you may have other issues. You may have an intake leak or exhaust leak. You may have fuel leaking into the carb thru the vacuum hose because of a defective petcock diaphragm or thru a defective Accelerator Pump diaphragm.((oldboy at Post#7 - http://xlforum.net/forums/showthread.php?t=2076811)) Be sure to double check the throttle plate position. | | + | | **Note - Trouble Finding A Change** - You may still have the throttle plate too far open, thereby running on the Transfer Ports instead of the Idle Port. But, if you have carefully set the throttle plate & still can't find a fall off until below 1/2 turn out, you need a smaller Slow Jet. If you can't find a fall off in idle until beyond 3-1/2 turns out, you need a larger Slow Jet. However, it is not recommended to use a smaller size than 42 nor larger size than 46. If the IMS setting appears to make no difference, you may have other issues. You may have an intake leak or exhaust leak. You may have fuel leaking into the carb thru the vacuum hose because of a defective petcock diaphragm or thru a defective Accelerator Pump diaphragm.((oldboy at Post#7 - https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/199875-turning-idle-mixture-screw-no-effect?t=2076811)) Be sure to double check the throttle plate position. | |
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| Doing a stage one upgrade with free flowing air cleaner and exhausts will create an even leaner condition than that from the factory configuration. In that case, start from general tuning and fix the overall lean condition. | Doing a stage one upgrade with free flowing air cleaner and exhausts will create an even leaner condition than that from the factory configuration. In that case, start from general tuning and fix the overall lean condition. | ||
| - | These comments on the XLForum are from Stevo ((Post#31 - XLForum thread: http://xlforum.net/forums/showthread.php?t=30561)) | + | These comments on the XLForum are from Stevo ((Post#31 - XLForum thread: https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/18344-cv-carb-mod-to-reduce-carb-farts?t=30561)) |
| | A carb fart is basicly caused by a lean condition... often from not having enough fuel when cold or from lack of vacuum from blipping or opening the throttle too quickly... (A mikuni will do it if you open it too quickly.) Too much air is entering the intake plenum for the amount of fuel for those particualr engine requirements at that point in time.. ie : it's too lean..\\ \\ The leaner [the condition]... the crisper [the fart]... until ya get too lean and then it pops thru the intake.\\ [On the other hand} A fart thru the exhaust or flat sound is usually from a rich condition.| | | A carb fart is basicly caused by a lean condition... often from not having enough fuel when cold or from lack of vacuum from blipping or opening the throttle too quickly... (A mikuni will do it if you open it too quickly.) Too much air is entering the intake plenum for the amount of fuel for those particualr engine requirements at that point in time.. ie : it's too lean..\\ \\ The leaner [the condition]... the crisper [the fart]... until ya get too lean and then it pops thru the intake.\\ [On the other hand} A fart thru the exhaust or flat sound is usually from a rich condition.| | ||
| - | And these from Chris Hajer ((Post#8 - XLForum thread: http://xlforum.net/forums/showthread.php?t=30561)) | + | And these from Chris Hajer ((Post#8 - XLForum thread: https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/18344-cv-carb-mod-to-reduce-carb-farts?t=30561)) |
| | When blipping the throttle, two things happen:\\ \\ 1. You are shooting some fuel in with the accelerator pump.\\ 2. When you blip the throttle, you are actually opening the throttle plate, and that larger opening causes a very [quick/temporary] minor drop in velocity through the carb and reduces the signal (vacuum, pull) across the fuel jets, so you flow less fuel for an instant. The accelerator pump is supposed to compensate for that somewhat. The problem is, with a very short stroke of the accelerator pump rod, like a blip does, not much if any fuel is actually shot, so the pump is not doing its job, in some cases. | | | When blipping the throttle, two things happen:\\ \\ 1. You are shooting some fuel in with the accelerator pump.\\ 2. When you blip the throttle, you are actually opening the throttle plate, and that larger opening causes a very [quick/temporary] minor drop in velocity through the carb and reduces the signal (vacuum, pull) across the fuel jets, so you flow less fuel for an instant. The accelerator pump is supposed to compensate for that somewhat. The problem is, with a very short stroke of the accelerator pump rod, like a blip does, not much if any fuel is actually shot, so the pump is not doing its job, in some cases. | | ||
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| **LINKS** | **LINKS** | ||
| - | * **IDLE DROP METHOD** of adjusting the CV carb idle mixture screw: [[http://xlforum.net/forums/showthread.php?t=31262]] ((Article from XLForum member chrishajer)) | + | * **IDLE DROP METHOD** of adjusting the CV carb idle mixture screw: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/18838-the-idle-drop-method-of-adjusting-the-cv-carb-idle-mixture?t=31262]] ((Article from XLForum member chrishajer)) |
| - | * Cantolina's Index List of Carb-related Threads: [[http://xlforum.net/forums/showthread.php?t=642408]] ((Article from XLForum member, cantolina, compiling articles from fellow members stevo, wedge, XLXR, merc, cantolina, IronMick, goldsport, chrishajer, Don Burton, gwcrim, Coolhaircut, Phillober , Johnny Wolf and biknut)) | + | * Cantolina's Index List of Carb-related Threads: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/84713-all-things-carburetor-tuning-jetting-how-to-sticky-index?t=642408]] ((Article from XLForum member, cantolina, compiling articles from fellow members stevo, wedge, XLXR, merc, cantolina, IronMick, goldsport, chrishajer, Don Burton, gwcrim, Coolhaircut, Phillober , Johnny Wolf and biknut)) |
| The Three Top Sticky Threads (in the order Cantolina has them): | The Three Top Sticky Threads (in the order Cantolina has them): | ||
| - | * **Read this First - Jetting 101**: [[http://xlforum.net/forums/showthread.php?t=49078]] ((Article from XLForum member Stevo)) | + | * **Read this First - Jetting 101**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/29446-read-this-first-jetting-101?t=49078]] ((Article from XLForum member Stevo)) |
| - | * **PLUG READING 101**: [[http://xlforum.net/forums/showthread.php?t=920271]] ((Article from XLForum member Wedge)) | + | * **PLUG READING 101**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/104264-plug-reading-101?t=920271]] ((Article from XLForum member Wedge)) |
| - | * **Carb basics and jetting by reading the plugs**: [[http://xlforum.net/forums/showthread.php?t=506958]] ((Article from XLForum member XLXR)) | + | * **Carb basics and jetting by reading the plugs**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/73013-carb-basics-and-jetting-by-reading-the-plugs?t=506958]] ((Article from XLForum member XLXR)) |
| - | * **Discussing Joe Minton Article about CV40 carb tuning**: [[http://xlforum.net/forums/showthread.php?t=1091101]] | + | * **Discussing Joe Minton Article about CV40 carb tuning**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/114343-by-the-numbers-american-iron-magazine?t=1091101]] |
| - | * **Carburetor Sticky Index on XLForum**: [[http://xlforum.net/forums/showthread.php?t=642408]] | + | * **Carburetor Sticky Index on XLForum**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/84713-all-things-carburetor-tuning-jetting-how-to-sticky-index?t=642408]] |
| - | * **CV Needle Drawings and Database**: [[http://xlforum.net/forums/showthread.php?t=165259]] | + | * **CV Needle Drawings and Database**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/46008-cv-needle-drawings-and-database?t=165259]] |
| * Post a thread of your own on XLForum.net with your information from above and ask for help in tuning your particular engine/carb combination | * Post a thread of your own on XLForum.net with your information from above and ask for help in tuning your particular engine/carb combination | ||
| - | * **Provide This Info When Asking About Tuning Carb'd Models**: [[http://xlforum.net/forums/showthread.php?t=1924896]] | + | * **Provide This Info When Asking About Tuning Carb'd Models**: [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/179137-provide-this-info-when-asking-about-tuning-carb-d-models?t=1924896]] |
| Sub-Documents | Sub-Documents | ||
| Line 590: | Line 590: | ||
| Insert the carb, attach the carb mounting bracket (which you are now confident will not distort the carb-to-manifold positioning), and bolt it all in place. | Insert the carb, attach the carb mounting bracket (which you are now confident will not distort the carb-to-manifold positioning), and bolt it all in place. | ||
| - | ((http://xlforum.net/forums/showthread.php?postid=5342857#post5342857)) | + | ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/181911-carb-questions?postid=5342857#post3887561)) |
| \\ | \\ | ||
| - | |||
| - | |||
| ===== Accelerator Pump ===== | ===== Accelerator Pump ===== | ||
| Line 618: | Line 616: | ||
| | 2004-2006 - 883 | 27777-04 | 27260-00 | 27577-92 | ::: | | | 2004-2006 - 883 | 27777-04 | 27260-00 | 27577-92 | ::: | | ||
| | 2004-2006 - 1200 | 27256-01 | 27260-00 | 27577-92 | ::: | | | 2004-2006 - 1200 | 27256-01 | 27260-00 | 27577-92 | ::: | | ||
| - | {{:techtalk:evo:carb:cv40-floatbowl-0304-ap.jpg?600|}} ((Discussion & pics from Robistro on the XLForum at http://xlforum.net/forums/showthread.php?t=2070191)) \\ | + | {{:techtalk:evo:carb:cv40-floatbowl-0304-ap.jpg?600|}} ((Discussion & pics from Robistro on the XLForum at https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/194022-cv-carb-float-bowl-accel-pump-2-models-id?t=2070191)) \\ |
| - | | {{:techtalk:evo:carb:xl1200s_keihin_cv_float_bowl_-_49_state_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) | Float Bowl P/N 27380-98 was used on\\ all 1998-2003 US version 1200S models.\\ These have no overflow tubes.\\ < < < --------------------------------------------- \\ \\ \\ \\ --------------------------------------------- > > > \\ Float Bowl P/N 27256-01, which has\\ an overflow tube, was used on the\\ 2001-2003 International version 1200S\\ models as well as every version 1200\\ model made from 2004-2006.| {{:techtalk:evo:carb:cv40-floatbowl-05-close.jpg?direct&220|}} ((pic from BestCoastXL of the XLForum http://xlforum.net/forums/showthread.php?t=2079110 post#943)) | | + | | {{:techtalk:evo:carb:xl1200s_keihin_cv_float_bowl_-_49_state_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) | Float Bowl P/N 27380-98 was used on\\ all 1998-2003 US version 1200S models.\\ These have no overflow tubes.\\ < < < --------------------------------------------- \\ \\ \\ \\ --------------------------------------------- > > > \\ Float Bowl P/N 27256-01, which has\\ an overflow tube, was used on the\\ 2001-2003 International version 1200S\\ models as well as every version 1200\\ model made from 2004-2006.| {{:techtalk:evo:carb:cv40-floatbowl-05-close.jpg?direct&220|}} ((pic from BestCoastXL of the XLForum https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/201980-hammer-1275-clang-noise-slow-oil-feed-kinked-crankcase-vent?t=2079110+post#943)) | |
| {{techtalk:evo:carb:cv40-accelpump-ckvalve.jpg|}} ((Annotated by IXL2Relax at the XLForum))\\ | {{techtalk:evo:carb:cv40-accelpump-ckvalve.jpg|}} ((Annotated by IXL2Relax at the XLForum))\\ | ||
| - | {{:techtalk:evo:carb:91_keihin_cv_accelerator_pump_jet_by_blackbikedave.jpg?direct&400|}} ((photos by BlackBikeDave, cropped-annotated by Hippysmack http://xlforum.net/forums/showthread.php?t=2024981)) \\ | + | {{:techtalk:evo:carb:91_keihin_cv_accelerator_pump_jet_by_blackbikedave.jpg?direct&400|}} ((photos by BlackBikeDave, cropped-annotated by Hippysmack https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/189871-1991-cv-carb-accelerator-pump-nozzle-cleaning?t=2024981)) \\ |
| Line 631: | Line 629: | ||
| ===== Fuel Float & Float Bowl Drain ===== | ===== Fuel Float & Float Bowl Drain ===== | ||
| - | {{:techtalk:evo:carb:cv40-float-info.jpg?300|}}((Pic from Cantolina of the XLForum http://xlforum.net/forums/showthread.php?t=14949 - Annotated by IXL2Relax)){{:techtalk:evo:carb:cv40-floatbowl-drainscrew.jpg?300|}}((Annotated by IXL2Relax)) | + | {{:techtalk:evo:carb:cv40-float-info.jpg?300|}}((Pic from Cantolina of the XLForum https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/9621-carb-adjusting-where-are-the-jets-and-the-mixture-screw?t=14949 - Annotated by IXL2Relax)){{:techtalk:evo:carb:cv40-floatbowl-drainscrew.jpg?300|}}((Annotated by IXL2Relax)) |
| The fuel float is created by a hollow plastic chamber. It moves on a hinge pin mounted to the carb body. It incorporates a TANG (metal tab) that operates the Float Valve. By adjusting the tang in micro-movements, it can raise or lower the fuel level that is maintained in the carb float bowl. See the adjustment specification & procedure [[techtalk:evo:carb02#setting_the_float_level|earlier in this page]]. | The fuel float is created by a hollow plastic chamber. It moves on a hinge pin mounted to the carb body. It incorporates a TANG (metal tab) that operates the Float Valve. By adjusting the tang in micro-movements, it can raise or lower the fuel level that is maintained in the carb float bowl. See the adjustment specification & procedure [[techtalk:evo:carb02#setting_the_float_level|earlier in this page]]. | ||
| Line 669: | Line 667: | ||
| {{:techtalk:evo:carb:cv40-enrichener-assy.jpg|}}((Pics from Phillober t=848307\\ & gm1ll t=1553245))((Annotated by IXL2Relax at the XLForum)) | {{:techtalk:evo:carb:cv40-enrichener-assy.jpg|}}((Pics from Phillober t=848307\\ & gm1ll t=1553245))((Annotated by IXL2Relax at the XLForum)) | ||
| - | An XLForum Thread discussing the replacement of the cable is here (but pics are missing): http://xlforum.net/forums/showthread.php?t=848307 | + | An XLForum Thread discussing the replacement of the cable is here (but pics are missing): https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/99252-replacing-the-choke-knob-enrichener-cable-with-pics?t=848307 |
| \\ | \\ | ||
| Line 680: | Line 677: | ||
| Reversion is created in the engine combustion cycle by the relationship between the cams and the exhaust system. Specifically, between the harmonic waves created in the exhaust pipes and the overlap of the exhaust valve about to close while the intake valve is already opening. This overlap period, where both valves are open at the same time, is usually extended in high lift cams, causing the exhaust system to have a great affect on the cylinder fill operation. The exhaust functioning can have a positive or negative affect. | Reversion is created in the engine combustion cycle by the relationship between the cams and the exhaust system. Specifically, between the harmonic waves created in the exhaust pipes and the overlap of the exhaust valve about to close while the intake valve is already opening. This overlap period, where both valves are open at the same time, is usually extended in high lift cams, causing the exhaust system to have a great affect on the cylinder fill operation. The exhaust functioning can have a positive or negative affect. | ||
| - | If/when reversion is occuring, the intake charge ends up passing through the carb three times: pulled in, pushed out, and pulled back in again. Each time it is picking up fuel making the mixture richer. ((Based on info from Aaron Wilson from the XLForum (aswracing) - http://xlforum.net/vbportal/forums/showthread.php?t=1028905 - Post#15)) | + | If/when reversion is occuring, the intake charge ends up passing through the carb three times: pulled in, pushed out, and pulled back in again. Each time it is picking up fuel making the mixture richer. ((Based on info from Aaron Wilson from the XLForum (aswracing) - https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-motor-top-end/110036-s1-lightning-heads?t=1028905 - Post#15)) |
| You can read more in the REF Section on [[techtalk:evo:carb04#exhaust_pipes_cams_-_power_or_reversion|Exhaust Pipes & Cams - Power or Reversion.]] | You can read more in the REF Section on [[techtalk:evo:carb04#exhaust_pipes_cams_-_power_or_reversion|Exhaust Pipes & Cams - Power or Reversion.]] | ||
| Line 694: | Line 691: | ||
| \\ | \\ | ||
| - | {{:techtalk:evo:carb:pilot_jet_chart_by_rocketmangb.png?direct&600|}} ((drawing by rocketmangb of the XLFORUM http://xlforum.net/forums/showthread.php?t=1710330)) \\ | + | {{:techtalk:evo:carb:pilot_jet_chart_by_rocketmangb.png?direct&600|}} ((drawing by rocketmangb of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/159523-cv-carb-pilot-jet-advice-afr?t=1710330)) \\ |
| \\ | \\ | ||
