HELP! 1990 johnson 70 no spark

[jcweis1]

hello new to this forum - always have had intermittent starting issues. Now it is worse. It started good this spring and ran well for a couple of days then it would not start. They next time I tried it with muffs it started fine then on the water would take it a few minutes to start. The next time on muffs it started great 5 times then it would act like it was running on one cylinder and died and would not start. I disconnected the blk/yellow wire that did not help, disconnected the large red terminal and jumped solenoid did not help. Spark plug tester show no spark on any cyl. replace power pack and it started good but then started cutting out then died and will not fire again. What should I try ?? really frustrated

[jcweis1]

Just in case: - the Johnson 70 is VJ70TLESB and the VLO is disconnected and capped off. Running mixed fuel. I can check ohms but not DVA

thanks for any help

the boat is not worth the cost of taking it to a shop but need it to run lol

[Joe Reeves]

Inspect closely the stator under the flywheel to see if it might be dripping a sticky looking substance down on the powerhead. That would indicate a meltdown that would result in a AC voltage drop to the powerpack capacitor which would in turn result in weak, erratic, and eventually no ignition/spark.

A stator when having a meltdown may function normally when cold... BUT... when hot will act as you describe.

[jcweis1]

Thanks Joe will try that next and let you know

[jcweis1]

Joe,

inspected the stator and it looks good. I checked the OEM resistance ohms readings on the stator and timer base and all checks out within range except for the white to green wire that had a resistance of 27 and the range is 9-21.
IS this enough out of range for it to be bad?

The ohms test on the new power pack reads consistent on all wires


Think I need to get a tester for DVA - man hate to

[Joe Reeves]

Frankly, throughout my years of working on these things, I always relied on a volt/ohm meter... never used a DVA... never had a problem diagnosing. Maybe I was just lucky.

Although the stator looks good, that reading indicates that something is amiss with it. Fortunately I always had spare (new) parts that I could try so it was no big deal for me to experiment with borderline failures... BUT... when one has to shell out $$$ for a component that may not be the problem, that's a tough pill to swallow!

A reading like what you listed above, when I encountered such a reading, it always proved to be a failing component. It would be great if you were friendly enough with a dealership that they would loan you the component to try.

[jcweis1]

Thanks Joe - I rechecked the ohms with another meter last night and all the readings for the stator and timer base were within the ranges specified by CDI Electronics. The Power pack readings were 78, 79.6 and 78. Appears good and white wire is shorted to GRD and the BRN & BRN/Yellow tested good.

I am at a loss. Is there a way to test the coils? I checked ohms on spark plug wires and they were good. Will coils sometimes fire and sometimes not? Seems funny all three would not fire - just at a loss what to think
Replaced all three spark plugs and after trying to start a few times - they are wet and no signs of having ever been fired. I did have a in-line spark tester that indicated no spark on all three cylinders

Will disconnecting the large red connection at the engine disable the ground at the boat controls to eliminate that possibility? I DON'T want to disconnect the BLK/YELLOW wire at the power pack - don't have a tool to remove the pin without damaging it.

Any thing else you would try? Thanks for your help

[Joe Reeves]

You can disconnect the black/yellow wire at the ignition switch OR simply unplug the large RED connector at the engine. However, I believe you've already done this haven't you?

Crank the engine by using a small jumper to go from the large battery cable terminal of the starter solenoid to the small 3/8" nut terminal of the solenoid that engages it.

Not likely that all three coils would fail at the same time. You could run a test using the engines components if at least one coil; was firing properly BUT with all coils not functioning, you would need a coil tester. You can however check the coils continuity readings as follows:

********************
(Magneto Capacitance Discharge Coils - Continuity Test))
(J. Reeves)

Check the continuity of the ignition coils. Remove the primary orange wire from whatever it's connected to. It may be connected to a powerpack screw type terminal, a rubber plug connector, or it may simply plug onto a small boss terminal of the coil itself.

Connect the black lead of a ohm meter to the spark plug boot terminal, then with the red ohm meter lead, touch the ground of the coil or the powerhead itself if the coil is still installed.

Then touch (still with the red lead) the orange wire if it's attached to the coil, or if it's not attached, touch the primary stud of the coil. You should get a reading on both touches (contacts). If not, check the spring terminal inside the rubber boots of the spark plug wire. Poor or no continuity of a coil is one reason for s/plug fouling.

********************

The engine must crank over at least 300 rpm in order for the stator to energize the powerpack. A slow cranking engine will not produce the proper ignition/spark the engine requires. All spark plugs must be removed to do the spark test properly.

[jcweis1]

yes, I did disconnect the BLK/Yellow wire before I replaced the power pack but didn't with the new power pack installed. I will disconnect the large RED connector and crank from the solenoid.

Will try the continuity of the coils tonight.

thanks

[jcweis1]

I appreciate all your advice Joe. The Johnson 70 is now running. The problem was all me. I first had rebuilt the fuel pump and the vacuum O ring that came in the kit was small compared to the old one but used it anyway. After the installation of that it didn't have spark so I bought a power pack. When I was installing the power pack decided to take the fuel pump apart and put the old O ring back in. Being that I was in a rush , it turned out that I had the fuel line connected to the vacuum port and the vacuum line connected to the fuel port. SO the whole time I was thinking it was a spark issue until I decided to spray a shot of starting fluid and it fired so it was only then I knew it was fuel. Doesn't pay to - be in a hurry and not think of other possible problems.

THANKS JOE