posted 06-09-2002 10:28 AM ET (US)
Just sold my '87 70 hp Johnson to a small shop and thought I would pass along how they checked out the motor.First, removed and looked at spark plugs.
Second, ran compression test on all three cylinders with starter spinning motor.
Third, with ingnition on, checked for spark in each spark plug.
Fourth, started motor. While running, took wire off of each spark plug to see if any change. Interesting, did this a few times on the middle cylinder.
Result, compression good, ignition good, middle carb needs cleaning.
I am sure they checked and noticed many other things, but the process was real straight forward.
Kelly