Re: 1966 650 prop shaft seal
I finally got the engine from one boat without a floor in it which was a v178 starfire to a 15' glastron not sure of the model and noticed there is a little oil around the propeller I am going to pull the prop after hooking everything up and finishing up the tilt/trim and throttle cables, it has the 2 lever controls. I would think if there is oil around the base of the prop then it must be the seals. I have read on here that it could be a couple different things I just wanted to see if it would be difficult or need special tools. I have really been trying to find a manual on this old engine under 75 dollars crazy the manual is more than some people pay for it. Thanks so much for your input Texasmark I have seen your posts on here and respect your knowledge and willingness to help us lets say less than knowledgable folk.
Thank you sir. Agree with your ensuring that the oil did in fact come from the prop shaft seal, and isn't exhaust blowby residue. A lower unit pressure test would answer your question but most of us aren't set up to make that test so we have to revert to more mundane means. Checking LU fluid is a good start before you tear into it. Whether or not the LU is full is an arbitrary question. Since no two people fill them the same and get the lower screw in at the same rate, preventing leakage, and overfilling to drive out the bubbles on top, you have no way of knowing.
I would just drain the LU oil and check it for color and metallic contamination. A lot of engines have a small magnet imbedded in the lower screw whose job it is to collect metal shavings. Expect some. If you use Quicksilver oil, it is blue black when new and over time if things are normal, it turns blacker...metal wear powder. If it looks like chocolate milk, you have water intrusion and the source could be bad prop seals. If you use the Pennzoil oil, it is clear honey colored. With water intrusion it may still be honey colored of sorts but wouldn't be clear.
Before you drain the oil, let the engine sit for as long as you can......several days. This allows the bubbles formed by operation to dissipate. They sometimes give you the impression you have a leak when you don't.
If the oil is normal looking, I'd just check it ever so often and see if it's leaking and if so how much. Maybe it's not all that bad. My experience with fixing things is that they can sometimes be better off left alone. Seems every time you touch something, you open yourself up for additional unexpected problems.
Good Luck,
Mark
