Chrysler 75hp no spark???

[Cdorlack]

Hello. My son hooked up the battery cables backwards on my 1981 chrysler 75hp outboard (the cables are both black) and attempted to start the engine. well nothing happened so he hooked them up the right way and the engine cranks but won't fire. I have no spark and ideas on what the problem is.

 

[jerryjerry05]

Welcome,
​What year and ignition system?
Pics?

It's possible you blew the regulator, disconnect it and see if it starts.
Start? Then replace it.

Also do a compression test. For some reason low comp on older Chryslers can cause a no fire situation??
​outboard ignition.com has test procedures. You'll need an analog meter for some test and a DVA meter for some others.

 

[Cdorlack]

The engine is a 1981 chrysler 75hp. Here is a pic of the type of ignition. This is the regulator I'm assuming what all should I disconnect.

 

[Cdorlack]

If I blew the regulator my ?is why would it start if I disconnect it or if it is bad

 

[Cdorlack]

Here are actual pictures of my motor. I disconnected the red and black wire for the regulator and the motor did not fire. The motor ran a week ago with no problems. I took the battery out of the boat to charge and when my son went to put the battery back in he hooked up the cables backwards and now no start/no spark.

 

[Nordin]

Hooking up the battery backwards can blow the CD box.
First check the autofuse /breaker and reset it.

Check the CD box by

1. Pull all plugs out.
2. Set throttle in idle position. (lowest possible position)
3. Put a screwdriver in top cyl. and turn the crank to TDC. (when piston is all way up)
4. Unscrew the White/black wire at distributor.
5. Turn ign.key in IGN.position. In this position there should be 12VDC at blue wire at the wiring terminal
6. Connect a plug to #1 HT wire from dist. and make good ground for the plug.
7. Scratch the White/black wire to ground. If CD box okey the #1 plug will fire/spark.

If no fire the CD box maybe bad.

 

[Cdorlack]

I have 12.55 volts coming out from the red wire from the distributor. Nothing coming out of the coil. 12.55 volts from the blue wire . 12.55 volts from the voltage regulator. All these readings are done with the key in the on position

 

[tommarvin]

It looks like the circuit breaker may be tripped, it's under the terminal block try pushing the tab on top in.
cdielectronics.com , outboardignition.com are good places to learn how to diagnose and test ignition parts and problems.
We wrapped red tape around our battery + power wire just to be safe.
When you turn the key does the starter turn the flywheel hard enough to start the motor.

 

[Nordin]

Cdorlack First we must use the right terminology for the parts. The blackbox with the ign.coil mounted on is the CD box, distributor has on this engine four HT wires.
One to the coil and three to the plugs. Rectifire/regulator are markt with a sticker "solid stat regulator". Black box with two thick red wires and two thin wires (black and yellow) is the starter solenoid.

IF you have 12,55VDC at red and blue wire at wire terminal the CD box has right feeding for proper work. Red is power for charging the capacitors in the CD box and blue is control and supplyvoltage for the electronic components in the box.

NOW unscrew the white/black wire from the distributor, put #1 cyl. in TDC and ground the plug at #1 HT wire, then scratch white/black wire to ground and look for spark at #1 plug.

Tommarvin IF 12,55VDC at red and blue wire at wire terminal, then the circuitbreaker is NOT tripped.

 

[Cdorlack]

Ok what dose it mean if I do the test and I have/don't have spark at #1 plug (NOW unscrew the white/black wire from the distributor, put #1 cyl. in TDC and ground the plug at #1 HT wire, then scratch white/black wire to ground and look for spark at #1 plug.)

 

[Nordin]

If the plug sparks ......CD box is okey.
If not........bad CD box.

 

[Cdorlack]

Ok is it possible that I fried the distributor. If so how do I test that . Sorry I'm new to boats and don't know a whole lot. Thanks

 

[Nordin]

No you can not blow the distributor. It only contains points and a rotor.
When you scratch the white/black wire to ground you simulate the points close and open.

If plug not spark when scratching the CD box is dead.
As I mentioned before in the thread, hooking up battery backwards ends mostly up in a bad CD box.

 

[Cdorlack]

Well I installed a used cd box and regular and she fired right up. Thanks for all the help guys