turns out they gave me the wrong seal,ordered one from Nissan,hope its right this time
From reported year, it should be 2-cycle. There was a recent thread on THT dealing with this topic:
Does the oil in the lower unit need to be drained when replacing the water pump impeller? there is a drain and a oil level screws on the lower unit.
Okay so it turns out the power head can't be rebuilt. The marine shop that worked on it before used a blue silicone sealant not heat resistant to seal
That is a big boat for a 10hp the 15hp carb will help. If you get it running good be sure and get the spacers for the leafs and install them. Otherwise