Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
|
techtalk:ih:carb01 [2019/10/08 02:06] hippysmack [Other HD Keihin Carburetors by Year Model] |
techtalk:ih:carb01 [2019/10/11 00:21] hippysmack [Sportster Keihin Butterfly Carburetors by Year Model] |
||
|---|---|---|---|
| Line 232: | Line 232: | ||
| * **The Accelerating Pump System**: The accelerating pump system works with sudden throttle openings (rapid acceleration) to quickly inject fuel into the carb to provide extra fuel for the engine demand. Rapid throttle action pushes the pump rod down, flexing the diaphragm, which compresses fuel underneath the diaphragm, forcing it up past the check valve and out the pump nozzle into the venturi. The check valve prevents backflow while the pump nozzle meters the flow. Spring action then returns the diaphragm back to it's original position. As the diaphragm returns, a new supply of fuel flows in and under it so the system will be ready to repeat the cycle with the next rapid throttle action detected. ((1970-1978 HD XL/XLH/XLCH/XLT 1000 FSM)) | * **The Accelerating Pump System**: The accelerating pump system works with sudden throttle openings (rapid acceleration) to quickly inject fuel into the carb to provide extra fuel for the engine demand. Rapid throttle action pushes the pump rod down, flexing the diaphragm, which compresses fuel underneath the diaphragm, forcing it up past the check valve and out the pump nozzle into the venturi. The check valve prevents backflow while the pump nozzle meters the flow. Spring action then returns the diaphragm back to it's original position. As the diaphragm returns, a new supply of fuel flows in and under it so the system will be ready to repeat the cycle with the next rapid throttle action detected. ((1970-1978 HD XL/XLH/XLCH/XLT 1000 FSM)) | ||
| * **The Choke System**: The choke is manually set by pulling out on the choke button. Pulled all the way out is fully closed (for cold engine), partially open (for warm engine) or pushed all the way in, fully open (for warm engine). ((1970-1978 HD XL/XLH/XLCH/XLT 1000 FSM)) | * **The Choke System**: The choke is manually set by pulling out on the choke button. Pulled all the way out is fully closed (for cold engine), partially open (for warm engine) or pushed all the way in, fully open (for warm engine). ((1970-1978 HD XL/XLH/XLCH/XLT 1000 FSM)) | ||
| - | * **Additional Tips** on usage: | + | |
| - | * Make sure the low speed and main jets are larger than stock to match the more free-flowing aftermarket exhausts and air filters we all seem to run. ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?threadid=659533)) | + | |
| - | * Do not run a worn out ignition auto advance unit. It makes carb farts that you would swear were lean low speed mixture.((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?threadid=659533)) | + | |
| * Integral Float Chamber | * Integral Float Chamber | ||
| * Manual Choke | * Manual Choke | ||
| * 3 different models | * 3 different models | ||
| * Model Year Changes | * Model Year Changes | ||
| - | * **Tuning** | ||
| - | * The usual method to set idle mixture/speed is: | ||
| - | * First: Set idle MIXTURE screw to 7/8 turns out. Get the bike hot. Set idle at comfortable speed with the idle SPEED screw. ((Hopper http://xlforum.net/forums/showthread.php?t=276157&page=2)) | ||
| - | * Second: Adjust the idle MIXTURE screw to the point where engine runs the fastest. This is optimum mixture. ((Hopper http://xlforum.net/forums/showthread.php?t=276157&page=2)) | ||
| - | * Third: Adjust idle SPEED screw again to get desired idle speed. ((Hopper http://xlforum.net/forums/showthread.php?t=276157&page=2)) | ||
| - | * The spring on the idle speed screw tends to creep the idle speed back up if you try to adjust the idle just that little bit slower. So I adjust the idle speed screw right down too slow, then nudge it up slightly faster until I get the speed I want, then it stays there. ((Hopper http://xlforum.net/forums/showthread.php?t=276157&page=2)) | ||
| - | * If your bike idles best with the idle mixture screw less than ½ turn open, you need a smaller low speed fixed jet. ((Hopper http://xlforum.net/forums/showthread.php?t=276157&page=2)) | ||
| - | * If your bike idles best with the idle mixture screw more than 1-1/4 turns open, you need a larger low speed fixed jet. | ||
| - | * This is real important. It also is the way to stop “carb farts” – spitting back or backfiring through the carb. | ||
| - | * If your Ironhead has aftermarket free-flow exhaust and airfilter on it, it will almost certainly need a larger low speed fixed jet, and most likely a bigger main jet too. But it is the low speed jet that affects the dreaded carb farts. Main jet affects mixture at wide open throttle and if left lean can overheat the engine, or burn holes in pistons. ((Hopper http://xlforum.net/forums/showthread.php?t=276157&page=2)) | ||
| - | |||
| - | |{{techtalk:ih:carb:hoppers_77_keihin_carb_pic_1.jpg?direct&300|}} |{{techtalk:ih:carb:hoppers_77_keihin_carb_pic_2.jpg?direct&300|}} | | ||
| - | |1977 Keihin 38mm non-CV pic 1((Hopper from the XLFORUM http://xlforum.net/forums/showthread.php?t=247853))|1977 Keihin 38mm non-CV pic 2((Hopper from the XLFORUM http://xlforum.net/forums/showthread.php?t=247853))| | ||
| ==== Sportster Keihin Butterfly Carburetors by Year Model ==== | ==== Sportster Keihin Butterfly Carburetors by Year Model ==== | ||
| Line 258: | Line 243: | ||
| |XLH, XLCH|Late 1976|27153-76((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|B50A ((HD Service Bulletin #M-713 dated June 10, 1977))|(140 std) ((HD Service Bulletin #M713 dated June 10, 1977)) \\ Optional jets ((HD Parts and Accessories Bulletin dated February 8, 1977)) \\ - 130, 135, 145, 150 \\ 155, 160, 165, 170, 175((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|100|7/8 ((HD Service Bulletin #M713 dated June 10, 1977))|Upper ((HD Service Bulletin #M713 dated June 10, 1977))| | |XLH, XLCH|Late 1976|27153-76((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|B50A ((HD Service Bulletin #M-713 dated June 10, 1977))|(140 std) ((HD Service Bulletin #M713 dated June 10, 1977)) \\ Optional jets ((HD Parts and Accessories Bulletin dated February 8, 1977)) \\ - 130, 135, 145, 150 \\ 155, 160, 165, 170, 175((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|100|7/8 ((HD Service Bulletin #M713 dated June 10, 1977))|Upper ((HD Service Bulletin #M713 dated June 10, 1977))| | ||
| |XLH, XLCH, XLT|1977-1978 |27153-77 ((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|B50B ((HD Service Bulletin #M-713 dated June 10, 1977)) \\ B50C |(160 std) ((1954-1977 HD Sportster Parts Supplement pg 2)) (165 std) ((HD Service Bulletin #M713 dated June 10, 1977)) \\ Optional jets ((HD Parts and Accessories Bulletin dated February 8, 1977)) \\ - 130, 135, 145, 150 \\ 155, 160, 165, 170, 175((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|75|1-1/4 ((HD Service Bulletin #M713 dated June 10, 1977))|Center ((HD Service Bulletin #M713 dated June 10, 1977))| | |XLH, XLCH, XLT|1977-1978 |27153-77 ((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|B50B ((HD Service Bulletin #M-713 dated June 10, 1977)) \\ B50C |(160 std) ((1954-1977 HD Sportster Parts Supplement pg 2)) (165 std) ((HD Service Bulletin #M713 dated June 10, 1977)) \\ Optional jets ((HD Parts and Accessories Bulletin dated February 8, 1977)) \\ - 130, 135, 145, 150 \\ 155, 160, 165, 170, 175((HD Sportster Parts Catalog XLH/XLCH 99451-78B))|75|1-1/4 ((HD Service Bulletin #M713 dated June 10, 1977))|Center ((HD Service Bulletin #M713 dated June 10, 1977))| | ||
| - | |XL, XLCH, XLS |1979|27469-78A ((1979 Harley Davidson Sportster Parts Catalog))|B83A \\ B83B|165 \\ 160 - above 4000' ((HD Service Buletin #M-730 dated June 15, 1978 - Instruction Sheet pg 2))|65 ((1979 Harley Davidson Sportster Parts Catalog))| | + | |XL, XLCH, XLS |1979|27469-78 ((1979 Harley Davidson Sportster Parts Catalog)) \\ 27469-78A ((1980 HD Sportster Parts Catalog -80 pg 17))|B83A \\ B83B|165 \\ 160 - above 4000' ((HD Service Buletin #M-730 dated June 15, 1978 - Instruction Sheet pg 2))|65 ((1979 Harley Davidson Sportster Parts Catalog))| |
| - | |XL, XLS|1980|27469-80A|B83D|160|65 ((1979-1985 HD XL Parts Catalog pg 23))| | + | |XL, XLS|1980|27469-80 \\ 27469-80A ((1981 HD Sportster Parts Catalog -81 pg 19))|B83C \\ B83D|160|65 ((1979-1985 HD XL Parts Catalog pg 23))| |
| - | |XL, XLS|1981-Early 1982|27469-81A|B83F|160|68 ((1979-1985 HD XL Parts Catalog pg 25))| | + | |XL, XLS|E81-E82 \\ L81-E82|27469-81 ((1981 HD Sportster Parts Catalog -81 pg 21)) \\ 27469-81A ((1983 HD Sportster Parts Catalog -83 pg 23))|B83E \\ B83F|160|68 ((1979-1985 HD XL Parts Catalog pg 25))| |
| |XL, XLS|Late 1982|27469-82|B83G|150|68 ((1979-1985 HD XL Parts Catalog pg 25))| | |XL, XLS|Late 1982|27469-82|B83G|150|68 ((1979-1985 HD XL Parts Catalog pg 25))| | ||
| |XL, XLS, XLX|E1983|27469-83|B83H|160|52 ((1979-1983 HD XL Parts Catalog pg 23))| | |XL, XLS, XLX|E1983|27469-83|B83H|160|52 ((1979-1983 HD XL Parts Catalog pg 23))| | ||
