mercruiser alpha one gen 1 shift problems

I just bought a boat that has a Mercruiser Alpha One Gen 1 outdrive. It will shift into reverse and into neutral just fine. It won't shift into forward though. I pulled the lower shift cable off of the lever and tried manually pushing and pulling on the shift cable end and get the same results. I pulled the outdrive off and can shift it into forward and reverse with no problem. I triple checked alignment with the two shift rods. Everything looks fine. I've owned a boat since I was 5 but this is my first inboard/outboard set up. I've read several of these posts to try to educate myself but I'm still having the same issue. I'd appreciate any help that anyone can offer.

Did you test drive it before purchase? With the drive off is the drives lower shoe in a straight line 12:00?
Broken lower shift cable

The lower shoe is in a straight line. I pulled the shift cable out completely to check for damage but it looks good. I didn't test drive when I purchased, but I did see it go into forward and reverse. I pulled the outdrive off to change the bellows and I can put it in forward and reverse by twisting the lower shift rod. I checked everything I can think that's involved with shifting... I think.

you physically removed the lower shift CABLE and not just the core? Have found core separation where the solid core comes thru the outer casing or the cable is broken just behind the gimbal housing where the shift cable screws in

click to enlarge

So last night, I went back to it and I did remove the entire cable, casing and all. As you mentioned, the casing is broken just between the housing where it threads in. I ordered a new one last night. Do you think that could be the cause of what I'm explaining?

Definitly, the pulling action in reverse pulls, when pushing for fwd, the casing moves but not the core

SNAP! I see exactly what you're talking about. Come Friday I'll have the new cable to install. Thanks. I'll update with the results once its all complete.