Evinrude 225 Twins No Spark

[notaclutoo]

I have a boat with twin Evinrude 225-HP Oceanpro model engines. It has been sitting covered for couple of years since last started. Fuel is still good and motors spin over fine, but I have no spark on either motor. I suspected the kill switch but it seems okay.

Tell me where to check for voltage between the ignition switch and the ignition module on the engine.

Here is the odd thing that has me stumped, there is fire on the top starboard sparkplug on both motors.

[jimh]

To have two engines both spontaneously develop a problem with their ignition systems in the same way seems unlikely. More likely an external element in the electrical system is causing a problem in both engines.

Older OMC engines won't generate spark until the flywheel rotation speed reaches a certain minimum threshold. Perhaps the cause of no spark is due to a weak battery that goes not crank the engine fast enough.

[jimh]

It is very difficult to describe complex electrical circuits in a narrative. To effectively work on electrical circuit problems you must have a wiring diagram. I recommend you obtain an OEM service manual while you still can. Call several Evinrude dealers to see if they have one in stock still on a dusty shelf in their storeroom. The service manual costs less than one hour of dealer technician time and will be a good investment.

As a general guide you can use wire insulation color to make an inference about circuit function. See my article on wire color codes in marine engines:

http://continuouswave.com/whaler/refere ... rCode.html

[johnyrude200]

If you have spark on one cylinder of both engines, you at least know the charge coils are working.

Make sure you have a fully charged set of batteries--at 12.6-Volts--so the cranking speed is high enough.

Evinrude 225 Oceanpro engines use an optical ignition system.

That both would behave the same is odd, but [the cause is] probably something simple a good local mechanic can spot. Coincidences do happen: I've seen oddball situations like this before in my repairs. If the cranking battery is good, it's possible the ignition key switch is failing due to corrosion or age. A bad key switch will create odd situations, despite testing OK.

A possible cause of no start is a position sensor that is off, but again unlikely the same defect occurs simultaneously on both motors. You can also take the pack leads and swap them to different coils to see if two (or four) packs have failed. They can and will fail without reason, rhyme, or warning.

[jimh]

While there are many possible causes related to components on the engines that can cause a no start condition, the notion that both engines developed spontaneously identical problems seems like a low probability, and the true cause is more likely to be due to some deficiency that is common to both and external to both, such as low battery voltage or a failed safety lanyard switch. Have you checked the safety lanyard and its associated switch?

[notaclutoo]

Thanks for the help guys. I bought a set of three new batteries before I began [to have this no-spark problem], so [low voltage from the battery is] not the [cause of this no-spark] problem. I have decided to carry [the Evinrude 225-HP engine] to my local Evinrude mechanic and let him repair it for me. Thanks again

[jimh]

The state of charge of a battery, not the age of the battery, determines if the battery voltage and stored charge are sufficient to crank the engine over at the minimum cranking speed necessary for generation of spark. You can deduce the state of charge of the battery by measuring the battery terminal voltage. A lead-acid 12-Volt storage battery that has full-charge should have a terminal voltage of about 12.6-Volts at rest without an external charging voltage having been applied for several hours.