Re: 1987 40hp johnson tune up help needed
If you haven't run this engine in a few years you need more than a tune up -- especially if the engine wasn't properly prepared for layup. If you intend to do this work yourself here's what you need to do:
1) Obtain a service manual
2) Remove, disassemble, soak, and thoroughly clean and reassemble the carbs with new kits.
3) If you have a portable fuel tank, drain and properly dispose of the old fuel and thoroughly clean the tank including the fuel pickup screen.
4) Replace the thermostat
5) Replace the water pump impeller.
6) drain and refill the lower unit lub.
7) Install new spark plugs.
8) Add fresh fuel/oil mix. If this is a VRO system that's still functioning, drain and clean the oil resevoir and add new oil.
9) Install a new battery or make sure the existing battery is still worth using and is fully charged.
You now stand a reasonable chance of having the engine fire and run reliably.
10) Once started, use a voltmeter to check voltage at the battery with the engine running at a fast idle. If the voltmeter reads less than 12.6 volts the charging system is not working.
