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techtalk:ih:engctl01 [2019/12/05 01:43] hippysmack [Timing Marks] |
techtalk:ih:engctl01 [2019/12/05 01:51] hippysmack [Timing Marks] |
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===== Timing Marks ===== | ===== Timing Marks ===== | ||
+ | Below are the timing marks on factory built engines. \\ | ||
+ | **However, don't trust any timing marks on flywheels till you have physically confirmed that (TDC.. is indeed TDC).** \\ | ||
+ | Over the course of the last 30, 40 and even 50 plus years, these engines could have had multiple makeovers by previous owners. \\ | ||
+ | Numerous modifications to the flywheels have been done or even been replaced with aftermarket wheels. \\ | ||
+ | The TDC marks as well as advance timing marks should be determined before trusting any marks on any flywheels that you didn't install yourself. \\ | ||
- | **All 57-71 Sportster 900 engines**: ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1427992)) \\ | + | **'Factory built' engines and there respective flywheel markings**: \\ |
+ | All 57-71 Sportster 900 engines: ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1427992)) \\ | ||
The single line is 45° BTDC front cylinder (original factory advanced ignition timing setting). \\ | The single line is 45° BTDC front cylinder (original factory advanced ignition timing setting). \\ | ||
The double lines are 15° BTDC front cylinder (used to set retarded kick start timing). \\ | The double lines are 15° BTDC front cylinder (used to set retarded kick start timing). \\ | ||
- | |||
The dot is TDC front cylinder (not used for any ignition settings). \\ | The dot is TDC front cylinder (not used for any ignition settings). \\ | ||
The dot is NOT rear cylinder advanced timing like on AMF big twin models. The AMF sportsters used double dots for rear advanced timing. | The dot is NOT rear cylinder advanced timing like on AMF big twin models. The AMF sportsters used double dots for rear advanced timing. | ||
- | **76-85 1000 engines**: ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1427992)) \\ | + | 76-85 1000 engines: ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1427992)) \\ |
The single mark is 40° BTDC (original factory advanced ignition timing setting). \\ | The single mark is 40° BTDC (original factory advanced ignition timing setting). \\ | ||