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techtalk:ih:carb01r [2019/09/13 21:23] hippysmack [Choke] |
techtalk:ih:carb01r [2019/09/20 18:16] hippysmack [Float Level Adjustment.] |
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| ====== Keihin Butterfly Carb (non CV) Functions, Adjustments, Tuning ====== | ====== Keihin Butterfly Carb (non CV) Functions, Adjustments, Tuning ====== | ||
| + | See also in the Sportsterpedia: \\ | ||
| + | * [[techtalk:ih:carb01#keihin_butterfly_or_non-cv_carb_late_1976-1987|Keihin Butterfly Carb Basic Information]] | ||
| + | * [[techtalk:ih:carb01q|Rebuilding a Keihin Butterfly Carb]] | ||
| + | * [[techtalk:ih:carb01p|Keihin Butterfly Carb Identificaton]] | ||
| + | |||
| For Late 1976-1987 Sportsters. \\ | For Late 1976-1987 Sportsters. \\ | ||
| If you are opening up your carb for the first time, you need three things: \\ | If you are opening up your carb for the first time, you need three things: \\ | ||
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| * The air cleaner backing plate must be flat against the carburetor flange gasket surface and the air cleaner mounting brackets must be adjusted and tightened properly per the FSM with no air leakage at the carburetor mounting flange. | * The air cleaner backing plate must be flat against the carburetor flange gasket surface and the air cleaner mounting brackets must be adjusted and tightened properly per the FSM with no air leakage at the carburetor mounting flange. | ||
| - | ==== High Altitude Modification Kit ==== | ||
| - | |||
| - | * Carburetor modification kits (including jet(s) and an accelerator pump stop screw) were made available for 1200cc, 1340cc and 1000cc models to provide leaner fuel mixtures when operating at elevations above 4000 feet sea level. ((HD Service Blletin #M-730 dated June 15, 1978)) | ||
| - | * Normally, leaner fuel/air mixtures are required for proper engine operation as the elevation above sea level increases. This high altitude kit (27096-79 for 1979 XLH (XL), XLCH, XLCR-1000) should be installed where there is evidence of a rich condition causing loss of smooth combustion, stumbling on acceleration or such other carburetor issues at high altitudes. | ||
| - | * The kit for Sportsters includes a #160 main jet, accelerator pump stop screw and the front down tube on the frame. | ||
| - | * Install and adjust the acc pump stop screw to extend 1/8" past hole in lever. | ||
| - | |||
| - | |||
| - | * Note, any motorcycle modified for high altitude operation must be converted back to standard if operated at altitudes below 4000 feet. An overly lean condition can cause engine damage. | ||
| ====== Idle Speed and Air/Fuel Mixture ====== | ====== Idle Speed and Air/Fuel Mixture ====== | ||
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| |After adjusting. ((photo by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))|Accelerator pump from the outside. \\ (see caution above) ((photo by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))|Check position of O-rings. ((photo by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))| | |After adjusting. ((photo by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))|Accelerator pump from the outside. \\ (see caution above) ((photo by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))|Check position of O-rings. ((photo by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))| | ||
| |{{:techtalk:ih:carb:keihin_butterfly_carb_15_by_hopper.jpg?direct&300|}}|{{:techtalk:ih:carb:keihin_butterfly_carb_16_by_hopper.jpg?direct&300|}}|{{:techtalk:ih:carb:keihin_butterfly_carb_17_by_hopper.jpg?direct&300|}}| | |{{:techtalk:ih:carb:keihin_butterfly_carb_15_by_hopper.jpg?direct&300|}}|{{:techtalk:ih:carb:keihin_butterfly_carb_16_by_hopper.jpg?direct&300|}}|{{:techtalk:ih:carb:keihin_butterfly_carb_17_by_hopper.jpg?direct&300|}}| | ||
| - | |||
| - | ====== Float Level Adjustment. ====== | ||
| - | |||
| - | The float needle should just kiss the seat with no extra pressure. \\ | ||
| - | Aftermarket float valves have a spring loaded pin under the float tab. \\ | ||
| - | So when the valve tip closes onto the seat, you can still push the valve down further. \\ | ||
| - | The valve should 'just' close when measuring the float level. Pushing further in from there will not close the valve any further. \\ | ||
| - | But it will cause you to set the float level wrong. The valve should be a light seat when measuring. \\ | ||
| - | Some aftermarket float needles with the spring loaded pin also have a defective neoprene tip on the other end, which does not seal even when set right. ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=1526333&highlight=float+level&page=4)) \\ | ||
| - | Since the tip on the needle on aftermarket ones don't work well, some would use the old original one (solid pin) to get a better measurement. ((Smerch of the XLFORUM http://xlforum.net/forums/showthread.php?t=1526333&highlight=float+level&page=4))\\ | ||
| - | Beats assembling the carb only to have it sit there and flood with gas. \\ | ||
| - | Also make sure you have the float valve for the correct type of Keihin carb. The CV valves are a little taller. \\ | ||
| - | {{:techtalk:ih:carb:float_valve_by_megadeth_-_labeled.jpg?direct&300|}} ((photo by Megadeth of the XLFORUM, labeled by Hippysmack http://xlforum.net/forums/showthread.php?t=1526333&highlight=float+level&page=3)) {{:techtalk:evo:carb:keihin_float_valve_comparison_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
| - | |||
| - | The measurement in the FSM is a reference point that will keep the OEM float within a fully open and fully closed position. \\ | ||
| - | Using aftermarket parts, you may have to adjust some. \\ | ||
| - | With carb in bike, you can put a small catch tin under it and turn on the gas and move the float until the flow of gas actually stops. \\ | ||
| - | (with no smoking or flames of course) \\ | ||
| - | You make the adjustment by bending the little tab that pushes on the end of the float needle. \\ | ||
| - | The -78 FSM specifies this distance as 9/16" to 5/8" (14mm-16mm). Setting the float lower will tend to make the carb act lean at low speed. \\ | ||
| - | Setting the float high can cause rich running, flooding and dribbles out the overflow line. \\ | ||
| - | |||
| - | Equally important is to set the wide open float setting by bending the other metal tag on the float by the pivot. It should be 28mm-30mm. \\ | ||
| - | This makes sure the float needle fully opens at full throttle openings and allows full fuel flow without starvation. \\ | ||
| - | It also stops the float hitting the bottom of the float bowl and possibly getting damaged. \\ | ||
| - | |||
| - | |Setting the float level. ((photos by Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=276157&page=3))|| | ||
| - | |{{:techtalk:ih:carb:keihin_butterfly_carb_18_by_hopper.jpg?direct&300|}}|{{:techtalk:ih:carb:keihin_butterfly_carb_19_by_hopper.jpg?direct&300|}}| | ||
