Need help finding a schematic for a boat's motor?

I am trying to find this schematic for this boat motor for my grand father, he really wants to work on it but any site we find that has the boat schematic we have to pay for it and sadly don't got the money to spare at the moment, but I am wondering if anyone can help me find the schematic for this Motor all the info It says is that its a mercury, model mark 25, ser# 1011019, a kiekhaefer that's all the motor says on it, I believe my grand father also said it was a 2 cylinder so an help finding a website that lets us see the schematic for free that would be much appreciated