On the rear of the motor unit near where all those white wires go you will find the 'down force'. Try increasing this a bit and see if it doesn't improve.

I have messed with those screws and there is no improvement. But just in case I tried what you said with the same result.

someone in my neighborhood can open my garage door, how can i change my remote that i use from my car?

I would consult your owners manual find it at this address

http://www.managemyhome.com/mmh/products/ManualSearchDisplay.action?sid=MMHMxSearsx00019

As for my problem it was a broken solder on the board which I fixed but thanks for the help.

Alright so after I repaired that solder it worked fine for a bit but now I doesn't open all the way and it somtimes closes all the way but no matter how far it closes it reverses. It works if I hit the button wait for it to reverse then hit the button twice quickly.

Maybe is time for a new opener, how old is your opener?

Here is a link that might be useful: Garage Door openers