Re: no spark 1994 evinrude 150
I have a 1994 150 hp too, should be simple to track down the trouble.
1.remove plugs connect a spark gap tester to a plug wire.(leave other plugs on wires touching block)
2.Disconnect the boat side harness and connect a remote starter unit(or use a small jumper wire). Check for spark. If the engine has spark, check the boat side harness's black/yellow wire for shorts to ground.
3.Disconnect the 5-pin connector on the port side of the power pack and see if the spark returns. If it does, use the fluke meter set to ohms and see if the black/yellow wires are shorted to engine ground.
4.Check the battery voltage on the yellow/red striped wire while cranking the engine. If below 11 volts, charge the battery or check all battery cables.
Yellow/red wire has to see 12v , it provides power to the optical ignition during cranking, below 11v you will not get spark, this wire is only live during cranking, its like a bypass. Look for corrosion omn terminals (battery/coils)
5.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.
6.Check the sensor eyes for dirt, grease and the like. If you need to clean it, use denatured alcohol and a Q-tip. Do not use any other cleaning agent because damage to the optical lens will occur.
7.Disconnect the voltage regulator/rectifier and retest. If the engine now has spark, replace the regulator/rectifier.
