CONTINUOUSWAVE

On a 1987 Mercury 2.0-liter 150-HP some of the stator wires have a “rubbery noodle” texture and flex response that is completely different from your ordinary under-the-cowl wires. I assume it is from age or degradation although everything was running fine like this for the past few years until a couple of weeks ago when it developed an occasional misfire during idle/low power, (runs smoothly at mid-high).

Has any seen this before? At least one knowledgeable person has said he has seen them like this brand new. Thoughts? Comments?

—Peter

It’s a stage of breakdown . I have had the exact same condition on two different motors, a 1983 MERCURY 50 HP and a 1988 EVINRUDE 88 SPL.

In both cases there is really no option other than replacement

Good to know, thanks.

The engineer in me would like to understand the physical process at play, but what you have given is a start.

I have since learned that the timer base is susceptible as well.

-Peter

My impression based on anecdotal reports of problems with the Mercury two-stoke-power-cycle outboard engines of the c.1980 era is the electrical components are likely to cause problems, which is not particularly unusual for any brand of outboard from that era, nor is it unusual for 20-year-old (or older) electrical components on outboard engines to need replacement.

The stator is located in a position of high temperature, and that also influences the aging of components.

Rubber noodle is better than what the older Mercury wires did over time. The stator wires along with most of the other wires in salt water conditions would literally crumble and break within 10 years or so. They were more like uncooked pasta.

There is widespread evidence that the “rubberizing” of outboard ignition system wires is not in any way limited to 1987 Mercury 150’s.

Food for thought.

-Peter

I am not sure “ignition wires” is the best term for the wiring from a stator coil. “Ignition wires” sounds more like high-voltage spark wires between a spark coil and a spark plug.

Are the spark plug wires also exhibiting decay?

The spark plug wires are not exhibiting signs of decay. Some of the other ignition system wires, specifically some of the motor ones associated with the stator and timer base/trigger can turn rubbery.

-Peter