You might want to check your advance mechanism, and make sure it is resetting all the way. The springs wear out sometimes. Or the weights no longer want to come back because of corrosion, or oblong holes, or worn pivot pins. Having too much advance will fire the plug before the piston gets close enough to the top, so the flywheel inertia can push it over and the gas can then expand. You also have to really give it a major effort kick to get the flywheel turning fast enough. It is a balance between kick back, and bottoming out and have the start arm start to travel towards the front of the bike. This is called "Sportster Knee". If the Rachet slips and you bottom out, it nearly breaks your knee. I don't know what the Start timing is supposed to be, since they have changed it over the span of years in my manual, and it does not cover your year. I would imagine it would need to be close to, but not past, TDC. maybe a few degrees advanced, say 4 or 5 degrees. The more towards TDC, the easier it will start while kicking. On the other hand, you will be moving the Max Advance as well as you adjust this. you will lose upper end performance if you go too far.
Answers & Comments
You might want to check your advance mechanism, and make sure it is resetting all the way. The springs wear out sometimes. Or the weights no longer want to come back because of corrosion, or oblong holes, or worn pivot pins. Having too much advance will fire the plug before the piston gets close enough to the top, so the flywheel inertia can push it over and the gas can then expand. You also have to really give it a major effort kick to get the flywheel turning fast enough. It is a balance between kick back, and bottoming out and have the start arm start to travel towards the front of the bike. This is called "Sportster Knee". If the Rachet slips and you bottom out, it nearly breaks your knee. I don't know what the Start timing is supposed to be, since they have changed it over the span of years in my manual, and it does not cover your year. I would imagine it would need to be close to, but not past, TDC. maybe a few degrees advanced, say 4 or 5 degrees. The more towards TDC, the easier it will start while kicking. On the other hand, you will be moving the Max Advance as well as you adjust this. you will lose upper end performance if you go too far.
Good Luck!
Turbocouch