1983 Johnson 140 Horse J140TLCT No Spark.

[Jade Rose Papa]

I am a retired Jet Engine Mechanic but this Outboard stuff has me scratching my head. I have a 1983 Johnson Seahorse 140 with no spark. Bought the boat to have a little retirement enjoyment. Pulled the Plugs, Fogged the Cylinders, Rotated by hand several revolutions and let it rest. Plugs looked good spun her over with starter to clear excess from cylinders and reinstalled the plugs. Checking for spark there is nothing on all 4 cylinders. This boat had sat for several years under a carport and is in decent condition for its age. I watched a few you tube videos. Scratching the head increased..... I compression tested and all 4 cylinders are 85 to 90. she has been sitting a while and figured the numbers would come up once she runs a while. but back to the problem, No Spark. Some folks on forums talked about checking voltage on certain wires, but I don't have the same colors of wires they told me to check. I have a 5 wire block on right side of engine marked 1 through 5. If I understand this right, the Stator provides power to a rectifier then to a power pack then to coil then to plug . head starting to get sore from scratching... Should have bought a plane..... WHERE DO I START? Help and old Vet out please!!

 

[racerone]

Rectifier is not needed to make the spark.---The 12 volt battery is NOT involved in making the spark.-----The FAST spinning flywheel magneto generates spark.----First load test the battery.----Then inspect the starter motor.----Compression should be around 120 PSI +

 

[Jade Rose Papa]

Wow, I got a Trophy. I will Check the Battery, Starter Motor is working as advertised. Thank You

 

[Jade Rose Papa]

Wow, I got a Trophy. I will Check the Battery, Starter Motor is working as advertised. Thank You

I have spark, Checked some connections and cleaned a couple that looked a little suspect, Put a full charge on the battery. Compression is still around 90 on all four cylinders. next is fuel system....

 

[saltchuckmatt]

It's a 2 stroke....find another outboard. She's done.

Airplanes clime, then they level off and descend...outboards are going up hills all the time.

If you get it running at home nicely...that's great but under load she will try hard....but....

As fast as spark, corroded wires and terminals, coils....yada yada.

If you want to continue, purchase a spark GAP tester. Looking for 7/16 or so with a good blue arc. When you have a no spark by the way, I always disconnect the control box at the motor and jump it at the solenoid. That eliminates other issues.

Might look better on the wall.

Good luck.