goodforbrains
New member
Hi, I bought a very low hour ns90a. I'm figuring around a 1988. Serial #12934. It has been sitting for 3 years. The steering was extremely stiff as well as the tilt tube. I rebuilt the carbs with genuine Tohatsu kits. New plugs. Ran a small tank of 50:1 just to fire her up. I pre oiled the cylinders and turned it over by hand a bunch of times. I adjusted the timing and carb linkages as per the factory manual. She started right up and idled great. Lots of smoke at first, but she settled down after idling for a few minutes. Prior to starting, I bled the oil pump but the lines are old and oil stained, so I really couldn't tell if all of the air was out. Also it was difficult to even tell if oil was being pumped to the cylinders. Once she cooled for a minute I pulled the plugs and took a compression test. All cylinders were 120 psi. I was confident it was a good motor at this point. I took the powerhead off and pulled all of the midsection and bracket apart. I ordered all of the parts. I am now reassembling everything. New everything except for the head gasket. My question is how robust is the oil pump on these? My oil pump is the old style with 3 lines that run to the intake manifold in front of the reed valves. Somewhere around serial # 18000, Tohatsu changed the oil pump and intake manifold. The newer style has a single oil line that I think t's off with the fuel line before the fuel pump. Is there a benefit to the new style? Should I get a new style oil pump and intake manifold? Or just remove the oil pump all together and order a block off plate and premix? Any insight or personal experience would be great! Thanks for reading.
