Re: 1972 Evinrude 65hp -- Repair or Replace.
I own two 1972 Johnson 65hp motors. One is on my boat and used frequently, and one is in my shop awaiting refubishment.
My experience with these motors is that they can be great, if they are received in good mechanical condition. If the powerhead has no significant problems and the compression is high and even, that is a good starting point. The next most significant item on the motor is the gearbox. Since you have problems with yours, obviously you need to get the problem diagnosed.
The first thing I would say about this, is similar to what others have said - don't let the dealer type mechanics get you freaked out. The fact of the matter is that they don't like to work on these old motors, and the shop owners want to sell you something, be it a late model used motor or a new one. When I bought my first J65, I was extremely busy with life and didn't have the time to do the intial refurbishment, so I took it to an OMC/BRP dealer that I had a long relationship with. The lead mechanic there actually bitched openly about the motor, and told me I had junk and would regret the purchase, etc. When I came back with my boat to get the motor mounted on it, all the other mechs kept telling me that I had found an exceptional motor. They were right, I have been running it for a couple of years now and am extremely pleased with it.
Sometimes you can find a retired OMC mechanic who still dabbles in repairs to supplement social security, or just to maintain an active lifestyle. These folks are gold when you have an older motor. I recommend that you go to the marinas in your area and "ask around." By doing so, you can not only find out who is available, but you can also find the good ones and avoid the hacks. You may find that the repairs to your gearbox aren't all that terrible. Even if it needs a new clutch dog and needs to be sealed, the cost should be bearable - especially when compared to buying another motor that could have hidden problems. Even if the gearbox is not economically repairable, you can probably find a decent replacement via local listings, shop "boneyards," or the auction sites.
Another issue to consider is the ignition system. My experience has been that, if the motor still has the original parts, you will probably have to replace all of it at some point. After the initial refurbishment on mine (water pump, carb rebuild, link/sync, fuel pump, timing, etc.), that is what I ran into. The good news is that my life wasn't so nuts and I did the work myself. I also found that there are aftermarket sources (CDI & Sierra) for the parts at about half the retail price, when compared to BRP. Although I try to support my local BRP dealer as much as I can, I don't recommend buying such parts from dealers because the prices are ridiculously high, and the parts are made by the aftermarket guys anyway.
Something else that you should consider, is the shift switch in the control unit. The part is no longer available as a new item, unless you find a dealer with one as an NOS (new, old stock) part. This single part can be a deciding factor for some in whether or not to keep a motor, or buy it in the first place. That is exactly why the owner of my second motor sold it to me - his shift switch went bad and his mechanic told him that he would never find another, etc. The guy sold me the motor for $150 and it is otherwise in good shape. That being the case, I now have a motor that can be turned into a solid runner and, because I was looking ahead, I just happen to have another control unit that works fine, courtesy of an EBay seller. I guess my point is that this issue is something to be aware of, but its not the end of the world.
My advice to you is simply to have the motor looked over by a competent mechanic. You may have a motor that is worth hanging onto, and you may not. Whether it will be something that will require a relatively small amount of money to become reliable, or will become a "money pit," is something that the mechanic should be able to tell you after examining it. If you end up talking to someone that just wants to pronounce it DOA before looking it over, move on and find someone else.
A final point is that, if you have a reasonable amount of mechanical apptitude, and feel that you could work on this motor yourself, you will improve the financial aspect of refurbishing it greatly. I have a couple of thousand dollars in the J65 that is on my boat, but a good part of that is in shop time during the intial work. If I had done all of the work myself, my investment at this point would be about $1,300. Considering that it now runs as well as anyone else's $7,000, late model 70hp motor (and will probably last longer), I consider that to be a bargain.
To both of you who posted here about owning a '72 OMC 65hp, please feel free to PM me with questions. I don't claim to be a complete expert on the motors, but I have been through most of the issues that crop up with them, so I can probably help most of the time.
