No Spark - '92 PS205

[d2jp]

Just completed tune-up with new cap, rotor, wires, coil, plugs. All part numbers confirmed and doubled checked with Richard at skidim. 529hr on 351w, 285HO. Timing was set to 10deg BTC, boat fired right away and idled perfectly. Great day on the water yesterday.

The key was accidentally left in the ON position last night, for about 15hrs. This is the only 'anomaly' in regards to this morning. I record the hours on my phone when I filled up yesterday, I was surprised that the hour meter had not run all night, the hours seems to be approximately what they were when we got off the lake. OK, now the fun stuff...........

This morning, no spark. Installed an inline spark tester on #1 plug to confirm no juice. Also, fuel gauge didn't move and neither did tach. I checked all the basics, then decided to pull out the safety switch. I confirmed it's toast, not sure if the key being on for so long is just a coincidence or related? I jumped the purple wires (which have 12.2v) at the safely switch and in doing so, the fuel gauge and tach now move as they should when the key is ON or CRANK position, but there is still no spark......moving on I have:

12.8v across battery terminals (read at end of day of no-start cranking)
7.8 volts at + terminal on coil
Coil resistance is .8 primary, 11.3 secondary
Main ground from batt to block is in good shape, ground from starter relay to block is in good shape

I'm going to pull the dash and check the ignition switch, and grounds.

Other ideas on the low coil voltage and what to check?

Thanks!

Jack

[Table Rocker]

I would start by concentrating on the coil. If you have power to the positive side of the coil, your boat can run (electrically speaking). You have 7.8 volts there (I assume you have a ballast resistor and a coil that requires one).

The other side of the coil should be a pulsing ground as the distributor turns. If you have a test light, put the clamp on 12v and the probe on the (-) post of the coil. As you crank the engine, the light should flash.

I don't know if your boat is points or EI. If points, the light staying on means your points aren't opening. Light staying off means they aren't closing.

[d2jp]

I would start by concentrating on the coil. If you have power to the positive side of the coil, your boat can run (electrically speaking). You have 7.8 volts there (I assume you have a ballast resistor and a coil that requires one).

The other side of the coil should be an intermittent ground as the distributor turns. If you have a test light, put the clamp on 12v and the probe on the (-) post of the coil. As you crank the engine, the light should flash.

I don't know if your boat is points or EI. If points, the light staying on means your points aren't opening. Light staying off means they aren't closing.

I have the factory Prestolite breakerless electronic ignition, and just installed a new coil from skidim# 1230 on this page: http://www.skidim.com/Ignition-Coils...products/1137/

Honestly don't know if there is a ballast resistor.

[Table Rocker]

I have the factory Prestolite breakerless electronic ignition, and just installed a new coil from skidim# 1230 on this page: http://www.skidim.com/Ignition-Coils...products/1137/

Honestly don't know if there is a ballast resistor.

I assume it uses a ballast resistor. If you have an electronic ignition, you probably need to use a LED test light with its own power source to check the (-) post on the coil.

I think your problem will be in the bottom half of your distributor. If your coil has voltage at the positive post, your wiring is doing it's job in that regard.

The ballast resistor is a white ceramic block with wires attached.

[d2jp]

I assume it uses a ballast resistor. If you have an electronic ignition, you probably need to use a LED test light with its own power source to check the (-) post on the coil.

I think your problem will be in the bottom half of your distributor. If your coil has voltage at the positive post, your wiring is doing it's job in that regard.

Thanks Table Rocker - I do have an LED test light. I will put it on there in the morning. I will pull the relay/breaker cover off the back of the engine and look for the resistor.

Another constant is that my tach has never been accurate, reading 3200rpm close to 40mph.

FYI - boat is still pretty new to me.

Edit: Found this thread, faulty EI module http://www.mastercraft.com/teamtalk/...ad.php?t=36522

[Table Rocker]

The ballast resistors I have seen have been out in the open. If you follow the hot lead away from your coil, you will find it pretty quickly.

[d2jp]

No ballast resistor. Three purple wires on the positive terminal: 1 to dizzy, 1 to choke, and one into the loom to the back of the engine harness and then I presume to ignition switch. Negative terminal has a gray wire I assume to tach and a black wire to distributor.


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[Table Rocker]

Without a ballast resistor, 7.8 volts at the coil is a problem. Check the voltage on the purple wire at the back of the ignition switch and see what you get with the key on.

[d2jp]

Pulled the dash/switch. Def not factory wire connectors so someone's worked here before. Screws to post were loose, tightened those. Now have 8.9v at coil.
Have 10.7v on purple wore at switch-and that post gets HOT temperature-wise in the ON position.
I've read that leaving the key ON can burn up the EI module - which could explain a lot about what's going on. Will test the EI module at the coil later after work.
Anyone know of/heard of key ON burning up the EI module?


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[Table Rocker]

Measure the purple wire tab with the wire off and the key to on.

[d2jp]

Reading voltage on switch tab with purple wire off is 11.8v.
Reading (-) post on coil with LED light and it's solid ground while cranking.
Jumped 12v from the battery to the (+) side of the coil, cranked and no spark.

[Table Rocker]

Reading voltage on switch tab with purple wire off is 11.8v.
Reading (-) post on coil with LED light and it's solid ground while cranking.
Jumped 12v from the battery to the (+) side of the coil, cranked and no spark.

It sounds like you found your problem. Hopefully you will be back running soon.

[d2jp]

Thanks Table Rocker - I heard back from skidim, Vince confirmed that key ON can burn up EI module and sometimes coil. The coil I have is an 0.8 ohm coil and that's the reading I got on the primary and 11.8 secondary....so it's not a dead short and I think I can reasonably assume I need a new EI module. Which isn't available for the old Prestolite so I'm going Pertonix and new coil (they recommend 0.6 ohm).

[lesslaw]

EI module is toast. When they go bad strange electrical things happen.

Gauge read wrong, voltages are strange, and there is no spark.

I have burned up a older EI module by changing the coil to a low resistance type.

Make sure your coil is the correct one for your new EI.

Good luck

Ben

[d2jp]

EI module is toast. When they go bad strange electrical things happen.

Gauge read wrong, voltages are strange, and there is no spark.

I have burned up a older EI module by changing the coil to a low resistance type.

Make sure your coil is the correct one for your new EI.

Good luck

Ben

Thanks for the insight Ben. I'm replacing mine with the Pertronix Ignitor II and their Flamethrower coil. I've had inconsistent tach readings for a couple weeks.