Boondox,
If you have the single spring on the rod above the door, like everyone else mentioned, they are under a lot of pressure when the door is closed.
The best way I've found to adjust the spring is to do it with the door fully open. You then work from the gap between the door and the header. With the door fully open, the tension on the spring should be pretty much nothing. As the door lowers the tension gets higher.
For the opener to work correctly, the door shouldn't feel like it weighs more than about 10 pounds to lift.
Brian
If you have the single spring on the rod above the door, like everyone else mentioned, they are under a lot of pressure when the door is closed.
The best way I've found to adjust the spring is to do it with the door fully open. You then work from the gap between the door and the header. With the door fully open, the tension on the spring should be pretty much nothing. As the door lowers the tension gets higher.
For the opener to work correctly, the door shouldn't feel like it weighs more than about 10 pounds to lift.
Brian