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techtalk:ref:svcproc20 [2024/01/21 21:21] hippysmack |
techtalk:ref:svcproc20 [2024/01/22 05:24] (current) hippysmack |
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| * The compression tester has a one-way valve in it's hose, allowing it to see the pressure of the compression stroke\\ but not relieve it on the other strokes. Additional strokes that produce higher pressures will increase the\\ reading of the gauge. | * The compression tester has a one-way valve in it's hose, allowing it to see the pressure of the compression stroke\\ but not relieve it on the other strokes. Additional strokes that produce higher pressures will increase the\\ reading of the gauge. | ||
| - | * Always look for a compression tester that has it's check valve as near to the chamber as possible. Otherwise, you're\\ adding the volume of the hose (up to the check valve) to the chamber volume which causes the compression reading\\ to be lower, because the piston is trying to fill that hose space as well as the chamber. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=26208&page=2)) | + | * Always look for a compression tester that has it's check valve as near to the chamber as possible. Otherwise, you're\\ adding the volume of the hose (up to the check valve) to the chamber volume which causes the compression reading\\ to be lower, because the piston is trying to fill that hose space as well as the chamber. ((aswracing of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-motor-top-end/15672-four-strokes-and-leak-down-compression-tests-how-they-work/page2?t=26208&page=2)) |
| * A proper compression test should be done with the engine close to normal operating temperature, when possible. ((79-85 HD XL/XR FSM pg 3-10)) | * A proper compression test should be done with the engine close to normal operating temperature, when possible. ((79-85 HD XL/XR FSM pg 3-10)) | ||
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| ====== Test Each Cylinder for Compression ====== | ====== Test Each Cylinder for Compression ====== | ||
| - | - Ride the bike to get the engine up to operating temperature. ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=48311)) | + | - Ride the bike to get the engine up to operating temperature. ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/29105-cylinder-compression-and-leakage-tests-for-your-ironhead?t=48311)) |
| - Disconnect the power to the coil to prevent it from firing. | - Disconnect the power to the coil to prevent it from firing. | ||
| - | * The extra two plugs (on dual plug heads) need to remain in place during this test. ((IXL2Relax of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005378)) | + | * The extra two plugs (on dual plug heads) need to remain in place during this test. ((IXL2Relax of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/188118-compression-test-1200s?t=2005378)) |
| * If you can't disconnect power to the coil, ground out all the plug wires. | * If you can't disconnect power to the coil, ground out all the plug wires. | ||
| - Clean the area around the spark plugs __BEFORE__ you remove them. ((79-85 HD XL/XR FSM pg 3-10)) | - Clean the area around the spark plugs __BEFORE__ you remove them. ((79-85 HD XL/XR FSM pg 3-10)) | ||
| - | * If you haven't disconnected the coil, you can insert the plugs into the plug wires and press the plugs against the cylinder heads for grounding. ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=48311)) | + | * If you haven't disconnected the coil, you can insert the plugs into the plug wires and press the plugs against the cylinder heads for grounding. ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/29105-cylinder-compression-and-leakage-tests-for-your-ironhead?t=48311)) |
| - Connect the compression gauge to the first cylinder. | - Connect the compression gauge to the first cylinder. | ||
| - Make sure the **throttle plate is fully open** (and the choke, if present) before turning over the engine. | - Make sure the **throttle plate is fully open** (and the choke, if present) before turning over the engine. | ||
| - | * If using a CV carb, **hold the slide up.** ((aswracing http://xlforum.net/forums/showthread.php?t=26208&page=2)) | + | * If using a CV carb, **hold the slide up.** ((aswracing https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-motor-top-end/15672-four-strokes-and-leak-down-compression-tests-how-they-work/page2?t=26208&page=2)) |
| * If the cylinder can't freely pull in air, the compression reading will be low. | * If the cylinder can't freely pull in air, the compression reading will be low. | ||
| * **Do NOT pull the enrichener knob** - The enrichener is mis-named a choke ('86-'06) but it is not a choke plate. | * **Do NOT pull the enrichener knob** - The enrichener is mis-named a choke ('86-'06) but it is not a choke plate. | ||
| - | - Crank the engine continuously through 5-7 compression strokes. (until there is no further increase in reading at the gauge) ((IronMick of the XLFORUM http://xlforum.net/forums/showthread.php?t=48311)) | + | - Crank the engine continuously through 5-7 compression strokes. (until there is no further increase in reading at the gauge) ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/29105-cylinder-compression-and-leakage-tests-for-your-ironhead?t=48311)) |
| - Record the readings at the end of the first and last strokes for this cylinder. | - Record the readings at the end of the first and last strokes for this cylinder. | ||
| - If you get a lower than normal reading, add app. 1/2 ounce of oil into the cylinder, repeat the compression test to see if the reading will increase. Record the oil-added readings. | - If you get a lower than normal reading, add app. 1/2 ounce of oil into the cylinder, repeat the compression test to see if the reading will increase. Record the oil-added readings. | ||
| - Repeat for the second cylinder. | - Repeat for the second cylinder. | ||
| - | {{techtalk:ref:svcproc:checking_compression_1_by_mathormell.jpg?direct&300|}} ((photo by MatHormell of the XLFORUM http://xlforum.net/forums/showthread.php?t=1976997&page=71)) {{techtalk:ref:svcproc:checking_compression_2_by_mathormell.jpg?direct&300|}} ((photo by MatHormell of the XLFORUM http://xlforum.net/forums/showthread.php?t=1976997&page=71)) | + | {{techtalk:ref:svcproc:checking_compression_1_by_mathormell.jpg?direct&300|}} ((photo by MatHormell of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/183888-hammerperf-90-in-the-works/page71?t=1976997&page=71)) {{techtalk:ref:svcproc:checking_compression_2_by_mathormell.jpg?direct&300|}} ((photo by MatHormell of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/183888-hammerperf-90-in-the-works/page71?t=1976997&page=71)) |
| ====== Interpreting the Readings ====== | ====== Interpreting the Readings ====== | ||
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| | Notes: The recorded results between the two cylinders should be within 10psi of each other.\\ PSI expectations are from HD manuals. ||||| | | Notes: The recorded results between the two cylinders should be within 10psi of each other.\\ PSI expectations are from HD manuals. ||||| | ||
| - | + | * Also, pay attention to how many pumps it takes to pump up each cylinder. ((wedge of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/134966-compression-test/page2?t=1457327&page=2)) Both cylinders should be relatively comparable. | |
| - | * Also, pay attention to how many pumps it takes to pump up each cylinder. ((wedge of the XLFORUM http://xlforum.net/forums/showthread.php?t=1457327&page=2)) Both cylinders should be relatively comparable. | + | |
| * Pumping up too fast means the exhaust isn't opening (pushrod worn too much or loose enough to fall out of place). | * Pumping up too fast means the exhaust isn't opening (pushrod worn too much or loose enough to fall out of place). | ||
| * Pumping up too slow is the usual suspect list below: | * Pumping up too slow is the usual suspect list below: | ||
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| **Possible Cause**: \\ | **Possible Cause**: \\ | ||
| Piston ring gap too tight upon installation. ((Jörgen)) \\ | Piston ring gap too tight upon installation. ((Jörgen)) \\ | ||
| - | **Full Article**: http://xlforum.net/forums/showthread.php?t=1567509 \\ | + | **Full Article**: https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/144544-white-smoke-from-pipe-and-ac-rattle-in-engine?t=1567509 \\ |
| - | **Pics of the Damage**: ((Photos by sep69 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1567509&page=2)) | + | **Pics of the Damage**: ((Photos by sep69 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/144544-white-smoke-from-pipe-and-ac-rattle-in-engine/page2?t=1567509&page=2)) |
| |{{techtalk:ref:svcproc:piston_damage_1_by_sep69.jpg?direct&300|}}|{{techtalk:ref:svcproc:piston_damage_2_by_sep69.jpg?direct&300|}}|{{techtalk:ref:svcproc:piston_damage_3_by_sep69.jpg?direct&300|}}| \\ | |{{techtalk:ref:svcproc:piston_damage_1_by_sep69.jpg?direct&300|}}|{{techtalk:ref:svcproc:piston_damage_2_by_sep69.jpg?direct&300|}}|{{techtalk:ref:svcproc:piston_damage_3_by_sep69.jpg?direct&300|}}| \\ | ||
| ====== Compression Calculator ====== | ====== Compression Calculator ====== | ||
| - | Article by aswracing of the XLFORUM ((http://xlforum.net/forums/showthread.php?t=1441757)) and Hammer Performance site. (( http://hammerperf.com/ttcompression.shtml)) \\ | + | Article by aswracing of the XLFORUM ((https://www.xlforum.net/forum/vendors/hammer-performance/133947-max-compression?t=1441757)) and Hammer Performance site. (( http://hammerperf.com/ttcompression.shtml)) \\ |
| [[http://hammerperf.com/ttcompression.shtml|Click here to download a free copy of the HAMMER PERFORMANCE Compression Calculator]]. \\ | [[http://hammerperf.com/ttcompression.shtml|Click here to download a free copy of the HAMMER PERFORMANCE Compression Calculator]]. \\ | ||
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| HAMMER PERFORMANCE assumes no responsibility for what you do with the information presented. \\ | HAMMER PERFORMANCE assumes no responsibility for what you do with the information presented. \\ | ||
| - | {{:techtalk:ref:svcproc:compression_calculator_screeenshot_1_by_aswracing.jpg?direct&400|}} ((screenshot by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1441757)) {{:techtalk:ref:svcproc:compression_calculator_screeenshot_2_by_aswracing.jpg?direct&400|}} ((screenshot by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1441757)) \\ | + | {{:techtalk:ref:svcproc:compression_calculator_screeenshot_1_by_aswracing.jpg?direct&400|}} ((screenshot by aswracing of the XLFORUM https://www.xlforum.net/forum/vendors/hammer-performance/133947-max-compression?t=1441757)) {{:techtalk:ref:svcproc:compression_calculator_screeenshot_2_by_aswracing.jpg?direct&400|}} ((screenshot by aswracing of the XLFORUM https://www.xlforum.net/forum/vendors/hammer-performance/133947-max-compression?t=1441757)) \\ |
