Need Help with TDC and Cam Timing for 77 Sportster
1977 Ironhead Sportster 1000
Ok the issue im having is I have my front cylinder on TDC confirmed that im spark plug hole and 3rd pic a dot in the timing hole. Now in the 2rd pic theres a little indention in the pinion shaft some say that needs to be at the 11o clock then install the gear with the line at the 11o clock also but if I put that indention at 11o clock then the rear cylinder will be at TDC and in the hole will be a line and not a dot, then put in all cam gears in and make sure all lines on cam gears are lined up correctly which is simple to do.
What im wondering is should I even worry about that grove in the pinion shaft and is there a purpose for it, like what I did above?
Which mark in the hole should I use?
DOT or LINE to use?
Front TDC or Rear TDC to time?
There are three separate procedures ... 1. Install The Pinion Gear
The mark on the pinion gear must be aligned with the mark on the pinion shaft. The mark on the flywheel is not used.
2. Install The Cam Gears
Do not use the ignition timing hole mark. Proceed as follows ...
Position the pinion gear mark at approximately the 11:00 position by rotating the engine. Use either the rear wheel or the kicker
Install cam #2 so that the mark lines up with the pinion gear mark. This may require moving the pinion gear mark a bit so they match perfectly
Temporarily, partially uninstall #2 while you install #1
Install #3, then #4 and finally the generator idler gear
When checking for the marks matching get down low and look straight on. Looking down at an angle may result in marks appearing to be correctly aligned when they are not.
The idea that installing cam gears is difficult or risky or to be feared is an internet myth. It may be based on installing cam gear #1 first simply because it is #1. It is important to start with #2 so that it and the pinion gear can be lined up before installing any other cam gears.
3. Set The Ignition Timing
This process is completely unrelated to installing the cam gears. It is unfortunate that that process if called "timing the cam gears" as it causes confusion with this process.
There are three separate procedures ... 1. Install The Pinion Gear
The mark on the pinion gear must be aligned with the mark on the pinion shaft. The mark on the flywheel is not used.
2. Install The Cam Gears
Do not use the ignition timing hole mark. Proceed as follows ...
Position the pinion gear mark at approximately the 11:00 position by rotating the engine. Use either the rear wheel or the kicker
Install cam #2 so that the mark lines up with the pinion gear mark. This may require moving the pinion gear mark a bit so they match perfectly
Temporarily, partially uninstall #2 while you install #1
Install #3, then #4 and finally the generator idler gear
When checking for the marks matching get down low and look straight on. Looking down at an angle may result in marks appearing to be correctly aligned when they are not.
The idea that installing cam gears is difficult or risky or to be feared is an internet myth. It may be based on installing cam gear #1 first simply because it is #1. It is important to start with #2 so that it and the pinion gear can be lined up before installing any other cam gears.
3. Set The Ignition Timing
This process is completely unrelated to installing the cam gears. It is unfortunate that that process if called "timing the cam gears" as it causes confusion with this process.
For setting cam timing the position of the piston and the location of the mark in the timing hole are completely irrelevant. Ignore them and follow my detailed instructions in the above post.
For setting the ignition timing follow the instructions in the link at the end of my post above. In these instructions is the information you need to position the front cylinder and the timing mark.
Got ya so set my cams put it together then set the ignition timing.. thanks.. I'm kinda confused on how the cover is suppose to be reinstalled also any tips or advice??
Please put the year of your IronHead into the info in the top right of your post, or in each question that you ask.
The ignition module or points assembly should have been removed before removing the cover.
Pushrods should have been removed, or at least set completely loose, before removing the gearcase [cam] cover.
Re-install the cover and the ignitiion components before locking in the pushrods.
11-27-2016, 03:46 AM
Need Help with TDC and Cam Timing for 77 Sportster
