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techtalk:evo:body02 [2022/05/17 08:33]
ixl2relax [Petcock (Fuel Outlet)]
techtalk:evo:body02 [2024/01/02 18:06] (current)
hippysmack
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 All 86-06 tanks (non-EFI EVO engines) use 22mm petcocks. EFI models (2007-later) have fuel pumps. (Some Ironhead tanks use 22mm petcocks.) All 86-06 tanks (non-EFI EVO engines) use 22mm petcocks. EFI models (2007-later) have fuel pumps. (Some Ironhead tanks use 22mm petcocks.)
  
-There are adapters available to replace the EFI fuel pump plate with a flat-plate to create a tank outlet for mounting a petcock. This may allow the use of a tank intended for EFI models on customized carburetored models. See this [[http://​xlforum.net/​forums/showthread.php?​t=1706950|XLForum Thread]].+There are adapters available to replace the EFI fuel pump plate with a flat-plate to create a tank outlet for mounting a petcock. This may allow the use of a tank intended for EFI models on customized carburetored models. See this [[https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​159272-efi-fuel-pump-block-off-plate-exists?​t=1706950|XLForum Thread]].
  
  
 **Reference Threads** **Reference Threads**
  
-http://​xlforum.net/​forums/showthread.php?​t=1969877\\ +https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-era-specific-and-model-specific/​frame-mount-evo-sportster-talk-1986-2003-models/​182878-peanut-tank-changes-early-90s?t=1969877 \\ 
-http://​xlforum.net/​forums/showthread.php?t=652141\\+https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-era-specific-and-model-specific/​frame-mount-evo-sportster-talk-1986-2003-models/​85360-sporty-tank-fitment?t=652141 \\
  
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 {{ :​common:​space100x5px.jpg?​direct&​2|}}{{ :​techtalk:​evo:​body:​petcock-filter.jpg?​direct&​400|}}\\ {{ :​common:​space100x5px.jpg?​direct&​2|}}{{ :​techtalk:​evo:​body:​petcock-filter.jpg?​direct&​400|}}\\
-The Petcock allows control of the fuel to the carburetor from the fuel tank. It has a 3-position lever to create OFF, ON & RESERVE settings. The **OFF** setting prevents fuel flow to the carb (used whenever the bike is not running). The **ON** setting allows normal fuel flow to the carb when the tank is above the reserve level. The **RESERVE** setting allows the final amount of fuel to be sent to the carb until the tank is empty. Normally, the petcock has an in-tank cylindrical mesh filter enclosing these inlets to prevent any dirt in the tank from clogging the intake of fuel. The tank and filter may be required to be cleaned from time to time. ((Pics from Carl-04XL here: http://​xlforum.net/​forums/showthread.php?​t=359788)) ​+The Petcock allows control of the fuel to the carburetor from the fuel tank. It has a 3-position lever to create OFF, ON & RESERVE settings. The **OFF** setting prevents fuel flow to the carb (used whenever the bike is not running). The **ON** setting allows normal fuel flow to the carb when the tank is above the reserve level. The **RESERVE** setting allows the final amount of fuel to be sent to the carb until the tank is empty. Normally, the petcock has an in-tank cylindrical mesh filter enclosing these inlets to prevent any dirt in the tank from clogging the intake of fuel. The tank and filter may be required to be cleaned from time to time. ((Pics from Carl-04XL here: https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-era-specific-and-model-specific/​rubber-mount-sportster-motorcycle-talk-2004-2006/​61501-fuel-reserve?​t=359788)) ​
  
 The petcock creates two levels of fuel supply in the fuel tank, the higher level being used for the ON setting and a low level being used for the RESERVE supply level. To do this, a short tube protrudes vertically into the fuel supply to create an ON level. A shorter tube (or the base of the petcock) is used to supply fuel ONLY when the petcock is set to RESERVE. By drawing fuel from the taller tube when the petcock is set to ON, a '​reserve'​ is created (usually between 10% & 20% of the tank size) below that tube level so as to warn the rider that the tank is running low on fuel. The petcock creates two levels of fuel supply in the fuel tank, the higher level being used for the ON setting and a low level being used for the RESERVE supply level. To do this, a short tube protrudes vertically into the fuel supply to create an ON level. A shorter tube (or the base of the petcock) is used to supply fuel ONLY when the petcock is set to RESERVE. By drawing fuel from the taller tube when the petcock is set to ON, a '​reserve'​ is created (usually between 10% & 20% of the tank size) below that tube level so as to warn the rider that the tank is running low on fuel.
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 This was considered a safety feature to help riders who forgot to turn the petcock to the OFF position (and to help prevent fuel spills in case of an accident or tipover). It was the recommended petcock for all optional tanks from 1992-1994. This style petcock was implemented on all stock tanks (of any size) from 1995 thru 2006 (2007-later used electrical fuel pumps). A vacuum of approximately 0.5-1.0 in. of Mercury (Hg) was needed to open the petcock for fuel flow.((2006 Factory Service Manual)) The OFF setting was still recommended whenever the engine was not running (to prevent accidental fuel flow from a faulty vacuum diaphragm). This was considered a safety feature to help riders who forgot to turn the petcock to the OFF position (and to help prevent fuel spills in case of an accident or tipover). It was the recommended petcock for all optional tanks from 1992-1994. This style petcock was implemented on all stock tanks (of any size) from 1995 thru 2006 (2007-later used electrical fuel pumps). A vacuum of approximately 0.5-1.0 in. of Mercury (Hg) was needed to open the petcock for fuel flow.((2006 Factory Service Manual)) The OFF setting was still recommended whenever the engine was not running (to prevent accidental fuel flow from a faulty vacuum diaphragm).
  
-{{:​techtalk:​evo:​body:​petcock-frtbk-vac.jpg?​direct&​400|}}((pic by ML414skidoo at http://​xlforum.net/​forums/showthread.php?​t=1862489)){{:​common:​space100x5px.jpg| ​ }} +{{:​techtalk:​evo:​body:​petcock-frtbk-vac.jpg?​direct&​400|}}((pic by ML414skidoo at https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-general-discussion-and-problems/​173551-1200-sportster-issues?​t=1862489)){{:​common:​space100x5px.jpg| ​ }} 
-{{:​techtalk:​evo:​body:​petcock-inside-vac.jpg?​direct&​200|}}((pic by JohnK at http://​xlforum.net/​forums/showthread.php?​t=1863271))+{{:​techtalk:​evo:​body:​petcock-inside-vac.jpg?​direct&​200|}}((pic by JohnK at https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​173730-vacuum-bypass-petcock-which-years-and-models?​t=1863271))
  
 Notice that the kidney-shaped cavity on the knob allows, in one position, the ON tube to flow to the outlet and, in another position, it allows the RES(erve) tube to flow to the outlet. The middle knob setting (as the switch is shown in the picture with the kidney-shaped cavity at the bottom only) is the OFF setting. If you look carefully inside the outgoing cavity of the petcock body, you can see the vacuum stud which allows fuel flow when the vacuum pulls the stud/plug open. The petcock is designed to ONLY FLOW FUEL when there is a vacuum applied. With no vacuum, the stud is in place and no fuel can flow, no matter where the knob is set. Notice that the kidney-shaped cavity on the knob allows, in one position, the ON tube to flow to the outlet and, in another position, it allows the RES(erve) tube to flow to the outlet. The middle knob setting (as the switch is shown in the picture with the kidney-shaped cavity at the bottom only) is the OFF setting. If you look carefully inside the outgoing cavity of the petcock body, you can see the vacuum stud which allows fuel flow when the vacuum pulls the stud/plug open. The petcock is designed to ONLY FLOW FUEL when there is a vacuum applied. With no vacuum, the stud is in place and no fuel can flow, no matter where the knob is set.
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 https://​serviceinfo.harley-davidson.com/​sip/​content/​document/​view?​id=1877\\ https://​serviceinfo.harley-davidson.com/​sip/​content/​document/​view?​id=1877\\
 https://​serviceinfo.harley-davidson.com/​sip/​content/​document/​view?​id=1419768648772055282 https://​serviceinfo.harley-davidson.com/​sip/​content/​document/​view?​id=1419768648772055282
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 ====Failures==== ====Failures====
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 **NOTE - PRODUCT RECALL:**\\ **NOTE - PRODUCT RECALL:**\\
-2005 Petcock Recall Notice - http://​xlforum.net/​forums/showthread.php?t=95982+2005 Petcock Recall Notice - https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-service/​sportster-motorcycle-recall-info/​-2000-s-sportster-recalls/​41158-2005-sportster-recall-fuel-system-gasoline-carburetor-system?t=95982
  
 Summary: Certain motorcycles may have been produced with defective fuel shut-off valves. The functionality of the '​ON'​ position and the '​Reserve'​ position of the valve may have been reversed. Summary: Certain motorcycles may have been produced with defective fuel shut-off valves. The functionality of the '​ON'​ position and the '​Reserve'​ position of the valve may have been reversed.
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 ====Bypassing the Vacuum Function==== ====Bypassing the Vacuum Function====
-If you prefer not to use the vacuum valve to control the fuel flow, you can disassemble the petcock & reverse the spring/​diaphram assembly. ((BKB of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?​t=1637859))+If you prefer not to use the vacuum valve to control the fuel flow, you can disassemble the petcock & reverse the spring/​diaphram assembly. ((BKB 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/​151807-vacume-petcock-question?​t=1637859))
  
 You would need to remove the four rear screws of the vacuum section. Remove the spring & remove the diaphragm. Then put the spring on the stud of the diaphragm (which normally operates as the plug) and reassemble the diaphragm back into place. The spring will now hold the diaphragm in an open position. Fuel should flow through the petcock without a vacuum line connected to it. You would need to remove the four rear screws of the vacuum section. Remove the spring & remove the diaphragm. Then put the spring on the stud of the diaphragm (which normally operates as the plug) and reassemble the diaphragm back into place. The spring will now hold the diaphragm in an open position. Fuel should flow through the petcock without a vacuum line connected to it.
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 There are also kits that replace the rear vacuum section of the petcock with a solid blank plate.\\ There are also kits that replace the rear vacuum section of the petcock with a solid blank plate.\\
-| Decman of the XLForum said: I had this bypass kit in my tool box.\\ It's a flat plate and rubber gasket. About a week after I installed it,\\ the bike started to stall after warmed up due to no fuel.\\ \\ When I took the petcock apart it was obvious that the center\\ of the rubber gasket was stretching and being pulled into the fuel\\ cavity and shutting off the fuel. Doh!\\ \\ So I just cut a hole in the center of the gasket and all is well.\\ After a quick search on the net I found that the new kits come with\\ the hole already there now. | {{:​techtalk:​evo:​body:​petcock-vacuumbypassplate.jpg?​300|}}((Pic from Decman - http://​xlforum.net/​forums/showthread.php?​t=1421879))|+| Decman of the XLForum said: I had this bypass kit in my tool box.\\ It's a flat plate and rubber gasket. About a week after I installed it,\\ the bike started to stall after warmed up due to no fuel.\\ \\ When I took the petcock apart it was obvious that the center\\ of the rubber gasket was stretching and being pulled into the fuel\\ cavity and shutting off the fuel. Doh!\\ \\ So I just cut a hole in the center of the gasket and all is well.\\ After a quick search on the net I found that the new kits come with\\ the hole already there now. | {{:​techtalk:​evo:​body:​petcock-vacuumbypassplate.jpg?​300|}}((Pic from Decman - https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​132709-vacuum-petcock-bypass-kit-failure?​t=1421879))|
  
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 ===== Vapor Valve (Tank Venting) ===== ===== Vapor Valve (Tank Venting) =====