Mercury 125 ELPTO will not start after reinstalling lower gear

[meuncleteooo]

Hi - I'm pretty new to owning a boat. I have a 2000 Mercury 125 ELPTO outboard motor serial 0T0088430. My brother took my boat out the other weekend and stated that the boat will not go in high gear, but will go on lower gear and reverse. After countless hours of researching online and can across a couple forums stated that my prop might have spun out, so I bought a new stainless steel prop. When removing the prop, I also removed the lower gear prop shaft to change out the O-ring due to is was broken. Now I'm trying to reinstall it. I pretty much put everything back together. Now my motor will barely crank but will not start. Everything I try to crank it I can see my prop moving in reverse. Please help if I did something wrong?:con fused:

Below is that link of the diagram of what I took apart and try to reinstall.

Boat Parts

[boats.net]

Something is in a bind in gearcase, need to recheck prop shaft installation.