02 johnson 90hp carb...no spark on any cylinder

[khes142]

Hi.
I have done post searchs for past info, and the following. keyswitch/lanyard circuit tests OK. Stator resistance tests ok for charging coil and ignition coil. motor ran fine for the first run of the season, for about 20 minutes, then a small backfire at 3000rpm, and then dead in the water. This is a 1726cc V4 with the optical ignition system. Anyone have any firsthand experience with this ignition. There is no DVOM meter test for the optical sensor. I have heard that it is prone to fail, as well as the powerpack for this system. All firsthand experience is appreciated. Motor is well maintained...there are no other issues affecting performance. Motor ran 110% until it suddenly lost all spark. thanks in advance.

 

[HighTrim]

Re: 02 johnson 90hp carb...no spark on any cylinder

I am going to assume you have already disconnected the black/yellow wire and then tested for spark from your comments. Have you disconnected the rectifier and then tried for spark? That would be your next step. What are the cranking RPM's? They must be at least 300. Check the power pack and ignition coil ground wires for corrosion and tightness. Polish them up then retighten. Disconnect the 4-pin connector on the port side of the power pack, and test again, does the spark return? Check the battery voltage on the Yellow/Red striped wire while cranking the engine, what is it at? Remove the sensor wheel and check for damage, especially where the top slots are located. Sometimes the wheels will break out where the windows overlap. Check the sensor eyes for dirt, grease, etc. If you find some, clean it off with a Q tip and alcohol. Disconnect the boat side harness and connect a remote starter unit. Check for spark. If the engine now has spark, check the boat side harness?s Black/Yellow wire for shorts to ground.

Let us know what you find.

 

[khes142]

Re: 02 johnson 90hp carb...no spark on any cylinder

thanks Chris, I will try all of the following today.