Power seat won’t go all the way forward

I recently sourced some electric "sport" seats to replace the electric base seats in my 128i. Installed last night and everything else is working but my DS seat stops short of moving all the way forward on the tracks. 

This means I cannot access the rear seat mounting bolt holes. The seat slides all the way back under power just fine but coming forward it stops about half way. 

So the motor gets power and moves both directions - just not all the way. I intend to remove the seat and inspect for a coin wedged in the track or something.

I am guessing there could be a stop screw or a hall sensor or something. Anybody have ideas?

My car has manual seats, so this is guesswork.

I am curious as to whether there are internal stops in the motors - it might be worth seeing if they run indefinitely or not with the rails removed. There is a seat position sensor (65779125897), but it relates to the airbag system, so I doubt it's the cause (but of course it could be, because BMW).

In reply to 02Pilot :

Thanks for the suggestion.

Figured it out. The breaker who I purchased the seats from had left the rear seat bolts dangling in the rails. They had gotten trapped, wedged half in the track and half in the bracket - which created a physical stop.