Ring inside Dolmar-Mikita oil pump

[Oloom7]

My dolmar 7900 oil pump does not work properly
I'm trying to repair it
I think it lost a ring inside the oil pump
is anybody here guiding me?

 

[huskihl]

There’s only one o ring in the kit. Use the control bolt with the biggest offset on the bottom if you want more oil from it

 

[Oloom7]

I did turn the bolt, didn't make any difference