Differences

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

--- techtalk:evo:carb02 [2020/08/06 03:36]
ixl2relax [The Idle/Transfer Ports Operation & Tuning]
+++ techtalk:evo:carb02 [2020/08/30 02:46]
ixl2relax [The Idle/Transfer Ports Operation & Tuning]
@@ Line 207: / Line 207: @@
     * Be sure to reinstall pump rod correctly
   * Be sure you have removed each part, cleaned the ports & reinstalled correctly
-  * Set the Idle Set Screw (located on the right side of the carb, near the throttle cables)\\ so that the Throttle Plate is between the Idle Port (one hole in the carb throat) and the\\ Transfer Ports (which consists of 5 holes nearby)
+  * Set the Idle Set Screw (located on the right side of the carb, near the throttle cables)\\ so that the Throttle Plate is closed as much as possible. Try getting it between the Idle Port\\ (one hole in the carb throat) and the Transfer Ports (which consists of 5 holes nearby).\\ Don't obssess over it if you can't.
+\\
+==== Setting The Float Level =====
-**Click on the small image below for the detailed instructions regarding 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.)\\
-{{:techtalk:evo:carb:hd-cv40-floatlevel-instructions.jpg?100|}}{{:techtalk:evo:carb:hd-cv40-floatlevel.jpg|}}
+{{:techtalk:evo:carb:hd-cv40-floatlevel-instructions.jpg?250|}}{{:techtalk:evo:carb:hd-cv40-floatlevel.jpg|}}\\
+**Click on the small image above for the detailed**\\
+**instructions regarding setting the float level:**
+{{: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))
+** Tip for Inspecting Float Level - With Carb Installed **
+HD advised of a tip for adjusting the float level thru Tech Tip #36 dated September 1993. \\
+However, this only works if you have an overflow fitting on the bowl (carbs for 1200S models don't have this fitting). \\
+  * Checking carburetor float level can be easily done without even removing the carburetor from the motorcycle.
+  * Simply attach a section of clear model airplane fuel line to the float bowl overflow fitting.
+  * A small diameter fuel line, which is compatible with gasoline, can be found in most hobby supply shops.
+  * Route the hose upward alongside the carburetor body.
+  * The motorcycle must be held level and be running to perform this test.
+  * Open the float bowl drain screw and fuel will rise in the hose to the same level as that in the bowl itself.
+  * In a carb with a properly adjusted float level the fuel level in this hose will be at the joint between the carb body and the float bowl face.
+\\
@@ Line 218: / Line 242: @@
   * Check intake seals on manifold (at heads) - replace now while it's apart
   * Check intake seal between manifold & carb - replace now
-  * Minimize Throttle Plate opening at idle - Set it between Idle Port & Transfer Ports [[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 [[http://xlforum.net/forums/showthread.php?t=1635658|(See this XLForum thread)]]
   * Check Idle Mixture Screw (IMS) screw/spring/washer/o-ring condition - clean port
   * Check IMS seat (Has the screw needle tip deformed the hole?)
   * Set initial IMS to 2-1/2 turns out from lite seat
-==== Inspecting Float Level - Carb Installed ====
-HD advised of a tip for adjusting the float level thru Tech Tip #36 dated September 1993. \\
-However, this only works if you have an overflow fitting on the bowl (carbs for 1200S models don't have this fitting). \\
-  * Checking carburetor float level can be easily done without even removing the carburetor from the motorcycle.
-  * Simply attach a section of clear model airplane fuel line to the float bowl overflow fitting.
-  * Small diameter fuel line, which is compatible with gasoline, can be found in most hobby supply shops.
-  * Route the hose upward alongside the carburetor body. The motorcycle must be held level and be running to perform this test.
-  * Open the float bowl drain screw and fuel will rise in the tube to the same level as that in the bowl itself.
-  * A carburetor with a properly adjusted float level will have the level the same height as the float bowl 0-ring surface.
 \\
 ==== Change the Screws ====
@@ Line 337: / Line 351: @@
-**Throttle Plate** - To assure the throttle plate is capable of closing completely, back out the idle set screw (on the side of the carb near the throttle cable cam) so that it is not limiting the closing of the throttle plate.* Make sure the throttle plate rotates smoothly with the throttle cable cam. Set the position of the throttle plate, with the idle set screw, so that the bottom edge of the plate is closed just past the transfer port holes and is thus located between the single idle port hole and the multiple holes of the transfer ports. In practice, this is easier on some CV40 carbs than others. Do what you can to keep the plate as closed as possible, but don't obssess on getting it exactly between those port holes. Your viewing angle is skewed when looking in there, anyway.
+**Throttle Plate** - To assure the throttle plate is capable of closing completely, back out the idle set screw (on the side of the carb near the throttle cable cam) so that it is not limiting the closing of the throttle plate.* Make sure the throttle plate rotates smoothly with the throttle cable cam. Set the position of the throttle plate, with the idle set screw, so that the bottom edge of the plate is closed as much as possible for setting the idle operation. Try getting it just past the transfer port holes and thus located between the single idle port hole and the multiple holes of the transfer ports. In practice, this is easier on some CV40 carbs than others. Do what you can to keep the plate as closed as possible, but DON'T OBSSESS on getting it exactly between those port holes. Your viewing angle is skewed when looking in there, anyway, so you see the hole before the plate is completely beyond it.
-(* If the throttle plate appears not to close fully with the idle screw fully wound out, carefully loosen the two throttle plate mounting screws, slightly. After the throttle plate is fully closed and has centered itself in the venturi, retighten the two mounting screws (don't overtighten & strip the threads). If by chance, for any reason, you have the throttle plate completely off, be aware that there is a right & wrong way to reinstall it. Be sure the plate is remounted with the right orientation because the top & bottom have an angled edge that needs to properly meet the carb venturi.)
+(* It doesn't happen often, but if the throttle plate appears not to close fully with the idle screw fully wound out, it may need to be recentered in the throat. Carefully loosen the two throttle plate mounting screws, slightly. After the throttle plate is fully closed and has centered itself in the venturi, start to retighten the two mounting screws (don't overtighten & strip the threads) while opening & closing the throttle so the plate squares up with the shaft but also recenters in the venturi. If by chance, for any reason, you have the throttle plate completely off, be aware that there is a right & wrong way to reinstall it. Be sure the plate is remounted with the right orientation because the top & bottom have an angled edge that needs to properly meet the carb venturi.)
 {{ :techtalk:evo:carb:cv40-imscap-drillbit.jpg?200|}}
@@ Line 530: / Line 544: @@
 {{: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)) \\
-**Fuel Float Hinge Pin** - Be very careful removing the hinge pin on which the fuel float operates. The pin is to ONLY be inserted in one direction. That direction is shown by an arrow embossed in the carb body. To remove the pin, press it out in the opposite direction from the embossed arrow. Be careful not to stress or break the mounting posts nor twist & damage the float arms.
+**Fuel Float Hinge Pin - CAUTION!** - Be very careful removing the hinge pin on which the fuel float operates. The pin should ONLY be REMOVED in one direction - the direction as shown by an arrow embossed in the carb body. To REINSERT the pin, press it into place in the opposite direction from the embossed arrow. Be careful not to stress or break the mounting posts nor twist & damage the float arms.
 **Float Bowl Overflow** - Notice the Overflow Tube on the bottom of the float bowl, in the [[techtalk:evo:carb02#working_with_cv40_carburetors|above picture]]. The channel used for the escaping overflow fuel was also used for a float bowl drain. The overflow was a safeguard against the failure of the float bowl valve from not closing. Should that happen, the fuel would be expelled onto the ground rather than being pushed into the intake manifold and filling the cylinders (and eventually the crankcase) with raw fuel.

Trace:

Differences

Navigation

Search

Toolbox