Re: 1973 65 hp johnson
Do a compression check on the motor and check the gearcase for signs of water (milky color oil) and/or metal shavings. Compression on these motors can often be in the 130 - 140 psi range, if the motor has been well taken care of. If you can get it running again, shift the motor to see if it goes in and out of each gear normally. If you can't get it running, pull the spark plug wires, remove the igntion key and check prop rotation by hand. Shift in/out of forward and reverse, while turning the prop by hand, to see if the motor locks into each gear. Look over the motor for obvious signs of mechanical problems.
If everything checks out, the motor may be a good candidate for fixing up. I would buy an OEM service manual as soon as possible. They are available from a variety of sources, including right here are iboats. If you don't want to tackle the carbs by yourself, your local OMC/BRP dealer will probably rebuild them, check/set link & sync, and time the motor for about $300.
I have a 1972 Johnson 65hp on my boat and am very pleased with it. My motor is nearly identical to yours, with the exception of the electric shift v. the mechanical shift in yours. Over a period of time, pretty much all of the replaceable items in mine were swapped out - water pump, fuel pump, carb rebuild, rectifier, coils, power pack, timer base, electric choke solenoid, auto choke disabled per OMC service bulletin, etc. Since the completion of the ignition system rebuild, the motor has run nearly flawlessly, and I expect to get many years of service out of it.
I think that you can have a similar experience with yours, so long as you have a mechanically sound motor to begin with. In fact, since your motor lacks some of the weak points of mine (hydro-electric parts availibility), your motor may last even longer.
