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techtalk:ref:svcproc21 [2018/08/30 22:17] hippysmack [Dynamic Leakage (into the crankcase)] |
techtalk:ref:svcproc21 [2019/01/09 04:09] ixl2relax ↷ Links adapted because of a move operation |
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| [[:techtalk:menu|{{ :techtalk:gototechnicalmenu.jpg|}}]] | [[:techtalk:menu|{{ :techtalk:gototechnicalmenu.jpg|}}]] | ||
| - | ====== REF: Troubleshooting - Engine - 04 ====== | + | ====== REF: Service Procedures 21 ====== |
| ====== Cylinder Leak-Down Test ====== | ====== Cylinder Leak-Down Test ====== | ||
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| * These are both fancy names for a deceptively simple process (installing an air gauge in the spark plug hole and noting the results). ((GOTWA of the XLFORUM http://xlforum.net/forums/showthread.php?t=26208)) | * These are both fancy names for a deceptively simple process (installing an air gauge in the spark plug hole and noting the results). ((GOTWA of the XLFORUM http://xlforum.net/forums/showthread.php?t=26208)) | ||
| * A compression test checks the cylinder's maximum pressure ability. A low reading reflects poor sealing of the chamber. | * A compression test checks the cylinder's maximum pressure ability. A low reading reflects poor sealing of the chamber. | ||
| - | * See [[techtalk:ref:trouble03|Performing a Compression Test]] in the REF section of the Sportsterpedia. | + | * See [[techtalk:ref:svcproc20|Performing a Compression Test]] in the REF section of the Sportsterpedia. |
| * Generally if a compression test shows anything suspect, the next step is a leak down test. ((milmat1 of the XLFORUM http://xlforum.net/forums/showthread.php?t=26208&page=2)) | * Generally if a compression test shows anything suspect, the next step is a leak down test. ((milmat1 of the XLFORUM http://xlforum.net/forums/showthread.php?t=26208&page=2)) | ||
| * A leak-down test checks the cylinder's ability to hold pressure (seal) and will reflect where the leak is occuring. | * A leak-down test checks the cylinder's ability to hold pressure (seal) and will reflect where the leak is occuring. | ||
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| * This will ensure that both valves are and will stay closed. \\ The bike will still move however as the piston is forced downward so you still may need to hold the brakes (unless you're testing with the piston at BDC). | * This will ensure that both valves are and will stay closed. \\ The bike will still move however as the piston is forced downward so you still may need to hold the brakes (unless you're testing with the piston at BDC). | ||
| - | **Remove the timing inspection plug from the crankcase**: This will be a listening area. | + | **Remove the timing inspection plug (57-03) from the crankcase**: This will be a listening area. |
| ** Remove the air cleaner**: Another listening area. \\ | ** Remove the air cleaner**: Another listening area. \\ | ||
| Line 168: | Line 168: | ||
| These are areas that should be leak free. | These are areas that should be leak free. | ||
| - | * **For leaking valves** | + | * **Leaking Valves:** |
| * Try pulling the rocker cover off and tap the valve ends with the wooden handle of a hammer. \\ That will identify a sticking valve. \\ If it keeps blowing that could indicate that the edge of the valve could be burned, a bad seat or a bent valve stem. \\ Really short pipes, pinging, carbon slathered valve edges, and such will cause burned valves. ((rick szymanski of the XLFORUM http://xlforum.net/forums/showthread.php?t=297440&page=2)) | * Try pulling the rocker cover off and tap the valve ends with the wooden handle of a hammer. \\ That will identify a sticking valve. \\ If it keeps blowing that could indicate that the edge of the valve could be burned, a bad seat or a bent valve stem. \\ Really short pipes, pinging, carbon slathered valve edges, and such will cause burned valves. ((rick szymanski of the XLFORUM http://xlforum.net/forums/showthread.php?t=297440&page=2)) | ||
| * If air is escaping through the valves: | * If air is escaping through the valves: | ||
| Line 174: | Line 174: | ||
| * Check pushrod length (86 and up engines). ((86 HD XL FSM pg 3-11)) | * Check pushrod length (86 and up engines). ((86 HD XL FSM pg 3-11)) | ||
| - | |{{:techtalk:ref:trouble:sticking_valve_3_by_73hardtail.jpg?direct&300|}}|{{:techtalk:ref:trouble:sticking_valve_4_by_73hardtail.jpg?direct&300|}}|{{:techtalk:ref:trouble:sticking_valve_5_by_73hardtail.jpg?direct&300|}}| | + | |{{techtalk:ref:svcproc:sticking_valve_3_by_73hardtail.jpg?direct&300|}}|{{techtalk:ref:svcproc:sticking_valve_4_by_73hardtail.jpg?direct&300|}}|{{techtalk:ref:svcproc:sticking_valve_5_by_73hardtail.jpg?direct&300|}}| |
| | Excess carbon between valve and seat causing a leak on this 73 XLCH. ((photo by '73hardtail of the XLFORUM)) ||| | | Excess carbon between valve and seat causing a leak on this 73 XLCH. ((photo by '73hardtail of the XLFORUM)) ||| | ||
| + | * **Blown Head Gasket**: | ||
| + | * A blown head gasket is usually accompanied by a chirping noise that keeps time with the pistons. ((doodah man of the XLFORUM http://xlforum.net/forums/showthread.php?t=2070472&highlight=compression+psi)) | ||
| ===== Dynamic Leakage (into the crankcase) ===== | ===== Dynamic Leakage (into the crankcase) ===== | ||
| Rings, by design, will allow air seepage even on a fresh motor so there will not be an instance where there is no air leakage past them. \\ | Rings, by design, will allow air seepage even on a fresh motor so there will not be an instance where there is no air leakage past them. \\ | ||
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| * Running and re-testing the cylinder may rotate the gaps out of alignment and yield higher psi readings. | * Running and re-testing the cylinder may rotate the gaps out of alignment and yield higher psi readings. | ||
| - | |{{:techtalk:ref:trouble:piston_rings_by_04xl1200c.jpg?direct&300|}}| | + | |{{techtalk:ref:svcproc:piston_rings_by_04xl1200c.jpg?direct&300|}}| |
| |Top 2 rings are lined up vertically on this piston ((photo by 04xl1200c of the XLFORUM http://xlforum.net/forums/showthread.php?t=1836174, edited by Hippysmack))| | |Top 2 rings are lined up vertically on this piston ((photo by 04xl1200c of the XLFORUM http://xlforum.net/forums/showthread.php?t=1836174, edited by Hippysmack))| | ||
| * **Ringland Failure**: | * **Ringland Failure**: | ||
| - | |{{:techtalk:ref:trouble:ringland_failure_by_aswracing.jpg?direct&300|}}| | + | |{{techtalk:ref:svcproc:ringland_failure_by_aswracing.jpg?direct&300|}}| |
| |This piston is just about to break from too much \\ cylinder pressure. This is from a race motor using \\ Nitromethane ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=616889))| | |This piston is just about to break from too much \\ cylinder pressure. This is from a race motor using \\ Nitromethane ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=616889))| | ||
| Line 210: | Line 212: | ||
| * **A hole in a piston would probably tell on itself** as in the pics below. \\ A dual psi gauge was set up at 92 psi, then the outlet was opened up, full hose, with the readings recorded in the second pic. \\ This left an inlet side 60 psi and outlet side of 48 psi while flowing from a small peanut air tank. It was more of a high pressure sound than a hiss. | * **A hole in a piston would probably tell on itself** as in the pics below. \\ A dual psi gauge was set up at 92 psi, then the outlet was opened up, full hose, with the readings recorded in the second pic. \\ This left an inlet side 60 psi and outlet side of 48 psi while flowing from a small peanut air tank. It was more of a high pressure sound than a hiss. | ||
| - | |{{:techtalk:ref:tools:hf_leakdown_tester_9_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:tools:hf_leakdown_tester_10_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:trouble:holed_piston_by_ironmick.jpg?direct&300|}} ((photo by IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=896763))| | + | |{{:techtalk:ref:tools:hf_leakdown_tester_9_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:tools:hf_leakdown_tester_10_by_hippysmack.jpg?direct&300|}}|{{techtalk:ref:svcproc:holed_piston_by_ironmick.jpg?direct&300|}} ((photo by IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=896763))| |
