[ElkLakePat]

I have what I believe to be a 1969 Kiekhaefer Mercury 650 65hp outboard motor serial No. 2716549. I am new to boating and outboard motors. It is on a Yar-Craft boat. Ran well all last summer. No problems, no motor smoking. Near the end of the year I had a guy come and get it winterized for the cold weather months here in Michigan and unfortunately I was not present when he did this yet my father was whom is a senior and all he can remember is the man told him that there was some water in the oil when winterizing it and it needed a seal replaced. Can anyone tell me what seal could possibly need to be replaced? Why my engine would run fine all summer long with what he said was a bad seal? Last if it does need a seal replaced what is entailed in this..is it costly and worth the efforts to replace. Any advice would be greatly appreciated. Thanks in advance.

[OV1961]

Originally Posted by ElkLakePat

Why my engine would run fine all summer long with what he said was a bad seal? Last if it does need a seal replaced what is entailed in this..is it costly and worth the efforts to replace. Any advice would be greatly appreciated. Thanks in advance.

The seals keep water out of the gear case. The motor will run with leaky seals but the lube will get contaminated and milky. You just need a lower unit seal kit, which will run about $150 maybe. Get a manual and a gear unit removal tool and you can do it yourself. If you want to pay someone to do it you will pay at least $500.

Keeping old outboards running is a labor of love that entails a lot of do-it-yourself work, otherwise if you are planning on spending money for other people to do repairs you might as well buy a newer motor.

[Fuzzytbay]

A leaking lower end seal should be changed, however, I have an older motor which I haven't changed the seal on, its used fairly regularly, ( has been for at least 4 summers) yet since I don't have the tools to do it, I haven't done it. Instead I change the gear oil more often then would normaly be required (about every couple of weekends). For the price of gear oil, its still cheaper than getting someone else to change the seal, or trying to find the right tools.
There is also the possibility the seal is fine, and the water in the oil came from years of sitting, and condensation occuring in the gear box. If it was my motor, I would use it for a while, then drain the oil, and see if its milky. Gear oil lubricates the lower end drive, if the oil is too thin, the lower end can heat up too much, and tell you with bang.

[ElkLakePat]

Thanks guys..I really appreicate the advice. I will put it back together and check the oil after a couple of weeks. Like I said, it ran great all last year. No problems at all.