1986 25hp Yam. ESJ no spark

[cheesehead4]

Please give some troubleshooting tips on this. (year, hp, model .. 86 25-ESJ)
Both plugs no spark. Safety switch is fine. It's not been run for almost 1 year and ran very good then. I've got a nice DVM but am unsure of various readings I should have at various components.

 

[99yam40]

Re: 1986 25hp Yam. ESJ no spark

Sorry, I have not worked on that old of a Yamaha so I do not know the components of the ignition system .
A manual for your motor will give the necessary info of how and what, but I believe you will need a DVA adapter for your DVM or the right peak reading voltmeter to read the peak voltages if it is like the newer ones .

 

[Ru4rusty2]

Re: 1986 25hp Yam. ESJ no spark

Get A DVA (Peak Reading Voltage) Adapter for your multimeter

When testing for Resistance (Ohms) Unhook The Battery

DVA tests should be done whlie cranking

Stator test

Brown to blue should read 120-150 Ohms

DVA should read 190v

Multimeter should be set to DC volts when using the DVA adapter

Trigger Test

Black to White/Red and Black to White/Black Should read 12-16 Ohms

Dva Should read 5v

Ignition Coils

Most Yamaha Plug wires are glued into the Ignition Coils so if you haven't already pulled them off. don't

Black to Black/White Primary Coil should read 0.5 Ohms +/- 10%

Black to end of plug wire Secondary Coil should read 3.5 Kilohms +/- 10%

CDI output Should be around 210v

Hope this helps

Chris

 

[cheesehead4]

Re: 1986 25hp Yam. ESJ no spark

My meter is a Fluke 115 true RMS. It has a min/max button.
Is this what you are talking about to record voltage peaks?

 

[Ru4rusty2]

Re: 1986 25hp Yam. ESJ no spark

Your Multimeter alone will not give a correct peak voltage reading you need an adapter DVA to check the voltage if not enough voltage it won't spark right.

http://www.stevensinstrument.com/peak_dva.htm

 

[cheesehead4]

Re: 1986 25hp Yam. ESJ no spark

At the river last week dead on the dock no spark. Pulled and prodded at all electrical stuff. Everything looked fine.
Crazy thing............. I assemble all the right gear to check this electrical problem. Today hit key in preparation for some diagnostic info and it fires right up. Can't fix what's not broken. Thanks for help. I'll post again should it quit with info.