Differences

This shows you the differences between two versions of the page.

--- techtalk:evo:carb02 [2021/06/23 06:58]
ixl2relax [Additional Tuning Notes]
+++ techtalk:evo:carb02 [2022/05/02 10:24]
ixl2relax [More on Jetting]
@@ Line 147: / Line 147: @@
 **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):
+^  Review These Considerations That Affect Tuning The CV40 Carburetor  ||
+^  Device Question  ^  These Are Possible Answers - Be Specific About Your Config  |
 |Engine Size |(Stk883, Stk1200, Stk1100, Stk900, Stk1000, Conv883-1200, Conv883-1250, etc.)|
 |Heads Installed |(Stock 883, Stock 1200, Specify Brand/Model)|
@@ Line 182: / Line 184: @@
 |Fuel Float Valve |(Y/N - Cleaned & Checked, Replaced)|
-| **TIP - 883 or 1200** ((Decman of the XLForum - xlforum.net/forums/showpost.php?p=3171730))\\ If you don't know your engine size, check it with a straw - Like this:\\ * Put in 5th gear\\ * Lift rear wheel\\ * Remove spark plugs\\ * Place a long plastic straw, chopstick, etc. in the spark plug hole\\ {{:techtalk:evo:engmech:measure-883-1200.jpg?120|}}\\ * Rotate tire to move cylinder to bottom dead center - lowest straw position\\ * Check cylinder diagonal dimension from far bottom of cylinder to top lip of spark plug hole\\ * 883 bore = 5.5" Diagonally ---- (Actual Bore Dia. is 3.000)\\ * 1200 bore = 5.875" Diagonally - (Actual Bore Dia. is 3.498)\\ The plastic straw is unable to 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 - 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.\\ |
 \\
@@ Line 231: / Line 233: @@
 ==== Setting The Float Level =====
-(Using a 1/2-inch spacer to lift the float side of the carb will approximate the 15°-20° angle needed.)\\
+(TIP: Using a 1/2-inch spacer to lift the float side of the carb will approximate the 15°-20° angle needed.)\\
-{{:techtalk:evo:carb:hd-cv40-floatlevel-instructions.jpg?250|}}{{:techtalk:evo:carb:hd-cv40-floatlevel.jpg|}}\\
+**Click on the small image below for a larger version of the detailed instructions regarding setting the float level:**\\
-**Click on the small image above for the detailed**\\
+{{:techtalk:evo:carb:hd-cv40-floatlevel-instructions.jpg?direct&250|}}{{:techtalk:evo:carb:hd-cv40-floatlevel.jpg|}}\\
-**instructions regarding setting the float level:**
+\\
 {{:techtalk:evo:carb:cv40-floatvalve-02.jpg?300|}}{{:techtalk:evo:carb:cv40-floatvalve-01.jpg?400|}}
@@ Line 277: / Line 278: @@
 Summary List:\\
+[[techtalk:ref:tools804#carburetor_intake_manifold_and_air_cleaner|Click Here]] for a full screw list on the fastener page in the Sportsterpedia.\\
 ea - 4mm x 16mm x .70TPI for Float Bowl\\
 ea - 4mm x 16mm x .70TPI for Top Diaphragm Cover\\
 ea - 4mm x 20mm x .70TPI for Top Diaphragm Cover at Throttle Bracket\\
 ea - 4mm x 10mm x .70TPI for Accelerator Pump\\
-Hex Head bolts use 3.0mm hex wrench\\
+Hex Socket Head bolts use 3.0mm hex wrench\\
 Button Head bolts use 2.5mm hex wrench
@@ Line 378: / Line 381: @@
 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.
-"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." - 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 [[http://xlforum.net/forums/showthread.php?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."
 **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.
@@ Line 388: / Line 392: @@
 {{ :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))
+**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.
 **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.
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 ====== More on Jetting ======
-Differences in pilot jets. \\
-{{: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)) \\
+Differences in pilot jets. \\
+See the Charts Here: [[techtalk:evo:carb01#slow_main_jets_-_p_n_comparisons|techtalk:evo:carb01#slow_main_jets_-_p_n_comparisons]]
 \\
+{{: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)) \\
+\\
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 [[:techtalk:menu|{{:techtalk:gototechnicalmenu.jpg|}}]]