Hello,I have problems with mz Johnson SeaHorse 140, the #2 spark plug (top left from behind) is totally fault-up after 5 - 10 minutes run, motor runs, but with low power. The piston looks that some material in the center is eaten up. When I insert a new plug, motor runs fine for 5-10 minutes and then same problem again. My dealer told me to bring the motor in and have new pistons installed, $2000.You can view pictures at: http://www.klempnauer.ab.ca/Johnson%20140.htm Hope for some help.Joerg Klempnauer
Port Charlotte FL but never the same since hurricane Charlie
Re: Johnson 140 Spark plug problems
Oops! Champions only in that motor!We need to go ahead and get it apart to measure the cylinders. Most likely the crank is OK so it should be just a standard rebuild.Once its back together we can run some tests to determine what actually caused the problem. It may be as simple as the wrong plugs or the plugs may only be one part of the answer.
Thank you Walker & Dhadley,Thank you for your help. This will be a winter job. Boating season, for me, is over, to much other work and I will leave this engine for christmas.One question, the engine has four barrels, each feeds in a combined crankcase senario or does each more or less feed one cylinder? If one is plugged or not so good that be the problem of to lean feed?Would you have the plug # for Champion?
Hello,We put the head back on. Tested all can's from behind top left 110, bottom left 115, top right 125, bottom right 125. This is cold. waiting for new plugs and may do a test run. Any way to test if the problem cylinder get's sufficient mix?