| Both sides previous revisionPrevious revisionNext revision |
techtalk:evo:body02 [2020/12/02 21:14]
– [Petcock (Fuel Outlet)] ixl2relax |
|---|
| Previous revision |
techtalk:evo:body02 [2024/11/19 02:17] (current)
– [Sub Documents] ixl2relax |
|---|
|
| ====== FUEL TANKS ====== |
| <font 14px/Arial, , ;;#800000>☚-----------------</font> <font 13px/Arial, , ;;#FF0000;;>**ALSO CHECK OUT THE TANKS IN THE**</font> [[gallery:tankart01| GAS TANK GALLERY]] <font 14px/Arial, , ;;#800000>—----------—-☛</font> |
|
|
| ==== Sub Documents ==== |
|
| * [[techtalk:evo:body02a|1996-2003 1200S Fuel Tanks (Decals & Paint)]] |
|
| ---- |
|
| \\ |
|
| Generally, you can _make_ tanks interchange between '82 to '03 - Mounting holes are at the same place, but some are rigid mount & others rubber grommet mount. |
|
ScrewOnly on fuel tanks for 2001-in Caps from 1992-later 2003 (which are generally interchangeable although some part number variations do exist over grommet-mounted) there is a 'Fuel Tank Ground Wire' (P/N 70118-97). It is supposed that this was added as a Static Spark Safety while refueling the various models and yearstank. |
|
All nonScrew-efi tanks use 22mm petcocksin Caps from 1992-later are generally interchangeable although some part number variations do exist for different models and years. |
|
| 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 with to create a tank outlet for mounting a petcockbung. This may allow the use of a tank intended for EFI models to be used on customized carburetored models. See this [[httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-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** |
|
httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-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 \\ |
httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/85360-sporty-tank-fitment?t=652141 \\ |
|
| \\ |
|
| ===== Petcock (Fuel Outlet) ===== |
|
| {{ :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: 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. |
|
| 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 httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-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 httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-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. |
|
**Bypassing There are a number of Petcock valves available, most using 62169-xx, where the vacuum function**: \\ |
If you prefer to xx is a number and revision letter. The older versions (like 62169-81) do not use a vacuum to flow fuel through the valve. Later, you can you can disassemble among the petcock & reverse the spring/diaphram assembly. (vacuum versions (BKB of the XLFORUM http:such as 62169-95/A/xlforum.netB/forumsC & 62169-02/showthreadA) there were versions with a left-direction fuel outlet tube while others have a downward fuel outlet tube. php?t=1637859)Some versions have a handle where the long portion is the pointer to the mode and others use the shorter end of the handle to indicated the valve mode (as in On, Off, Res). |
|
You would need **INSTALLING THE PETCOCK**\\ |
These petcocks use a multi-threaded nut to remove attach the four rear screws of petcock to the vacuum sectiontank. Remove One thread set is for the spring & remove petcock (fine threads) while the diaphragmother set is for the tank outlet (coarse threads). Then put The principle here is that as you thread the spring on nut onto the stud coarse threads of the diaphragm (which normally operates as tank, it is tightening faster there than the plug) and reassemble fine threads are unscrewing at the diaphragm back into placepetcock. This difference in thread tpi, pulls the petcock up against the tank outlet. The spring will now hold shoulder of the diaphragm inan open position. Fuel should flow through -tank filter functions as the seal between the petcock without and the tank (or there may be an additonal washer or o-ring as a vacuum line connected to itseal). |
|
If you remove You must wind the vacuum function from nut down on the petcock and you have one of before starting to attach the older models with a tee fitting in petcock to the vacuum line tank. Place the petcock close to (that goes but not against) the tank outlet. You want the nut to securely screw onto the VOES/MAPtank threads (several threads) , then remove before the tee and run a straight line from the carb vacuum nipple directly petcock is pulled tight to the VOES / MAPtank outlet. This minimizes any leak pointsAs you thread the nut onto the tank, it is unscrewing (more slowly) from the petcock. If you have a 2004-2006 model (start to thread the nut onto the tank outlet with the MAP sensor on petcock too far away, you will run out of threads before the intake manifold) and remove petcock is pulled tight to the vacuum function from tank outlet. If you start with the petcock too close to the tank, you can remove the vacumm line completely and simply cap petcock will be pulled tight to the vacuum nipple on tank after barely starting the carbnut onto the tank outlet. You're looking for a balance here. |
|
There are also kits that replace the rear vacuum section with It may take a blank solid plate. See this XLForum time or two of testing to see just how close you want the petcock to the tank as you start to thread : http://xlforumthe nut onto the tank outlet. net/forums/showthreadSuccess is when the petcock is properly tight to the tank with a relative equal number of nut threads holding onto the petcock and the tank outlet.php?t=1421879 |
|
| Additional References:\\ |
| Vacuum Operated Fuel Supply Valve Kit - (Instruction Sheet '-J02634' - Kit# 62169-95C)\\ |
| https://serviceinfo.harley-davidson.com/sip/content/document/view?id=1877\\ |
| https://serviceinfo.harley-davidson.com/sip/content/document/view?id=1419768648772055282 |
|
**====Failures:**\\==== |
| If you get fuel flow thru the petcock to the carb with no vacuum applied (in any petcock position), there is a problem with the petcock seals. |
|
|
| So, depending on exactly how the petcock fails, you might get a too rich or a too lean condition. |
|
Manual petcocks can also fail. They can leak fuel from the seals. They can collect debri debris on the filter screens. If the filter fails, it can allow debri debris into the operating petcock and clog the passages. |
|
| **NOTE - PRODUCT RECALL:**\\ |
2005 Petcock Recall Notice - httphttps://www.xlforum.net/forumsforum/showthread.phpsportster-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. |
|
\\====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 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. |
|
| If you remove the vacuum function from the petcock and you have one of the older models with a tee fitting in the vacuum line (that goes to the VOES/MAP), then remove the tee and run a straight line from the carb vacuum nipple directly to the VOES / MAP. This minimizes any leak points. If you have a 2004-2006 model (with the MAP sensor on the intake manifold) and remove the vacuum function from the petcock, you can remove the vacumm line completely and simply cap the vacuum nipple on the carb. |
|
| 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 - 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))| |
|
| \\ |
|
| ==== Troubleshooting ==== |
|
|
| \\ |
|
|
| ===== Vapor Valve (Tank Venting) ===== |
