Re: Changing Water Pump on '75 Johnson 85hp
This is a difficult model for a novice to service, you will certainly need a service manual. The shift rod is disconnected by seperating the two levers under the lower carburetor. You will need to remove the 3/8 nut and the 5/8 shoulder bolt, then seperate the levers. Be careful not to lose the nylon bushings in these levers, if they are not properly posititioned when re-assembled your motor will not go into gear right.
The thermostat is located under the exhaust cover in the back of the powerhead (this model uses a vernatherm and springs). Remember, this is a 33 year old motor, when removing the bolts securing the thermostat cover be very careful not to snap them off, they will be extremely difficult to remove if broken. Take your time, and consider some carefully applied heat (with a fire extinguisher handy, and don't use a torch inside the garage!) if it comes to that. There are springs, and grommets that will need to be replaced with the thermostat as well. There are a lot of small parts that need to be reassembled in the right order, have a pencil, and piece of paper handy and make a diagram of what goes where.
Like I said before, this is a difficult model to service, but you can do it!! just take your time, and pay close attention to what goes where, and make diagrams, or take pictures, you will be rewarded in the end. Also when you reassemble, put a little marine grease on the bolt threads, if you need to go back into it in the future it will come apart much easier.
Best of luck, Jimmy
