1997 Yamaha 6hp intermittant spark

rothfm

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I'm working on getting a factory manual, was hoping someone could point me to a couple specs in the meantime.

I'm usually on the Johnson/Evinrude board, my first Yamaha. I bout this motor for $75 bucks! Guy said no spark, otherwise its really like new condition and no Salt. Couldnt pass it up.

In testing, I first had spart, then not, then spark, no rhyme to reason. No obvious physical issues. The Previous owner has a new dual coil, wires, and plugs on it already. about 130psi on both holes.

Does anyone have the spec for ohm'ing out the "stator" leads , if that is what it is called on this engine. Or what the same might be from the "CDignition" box leads (which I'm assuming is like a powerpack")

Or anything else to look into, until I can get a manual. I hope the Yamaha manuals are as good as the OMC manuals.

Thanks
 

rothfm

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Thanks for that...I now remember that was out there on CDI. I'll measure tonight.
 

rothfm

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My Stator reads good (charge, and pulse coil sides) per the specs....As does the Secondary (small wires) orange and black of the dual Coil.

what Im not sure how to measure (spec is 6k-10k ohms) is the Primary side of the coil. /???

Pic attached, its a Dual Coil and the plug wires appear to be hardwired to it. Not sure what/where to measure to determine if the primary side is good--although it was replaced by Previous Owner already.

If the Primary side checks out...I've got to conclude its the CDI module but I've yet to see if there are any specs/readings for those leads.

I know its just resistance measurements, but I dont have a Peak Meter yet. I have the DCI troubleshooting Guide, and a version of a Yamaha owners manual. I'm pending a actual Service manual.

IMG_0925.JPG
 

rothfm

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Hoping someone has done this before or has one of these.....

Update:

across spark leads i get 8.2K ohms. I dont have a spec on that. Listings vary by year but doesnt specifically show 1997. Most orher years list about 3.5k ohms. Still a question there

So only thing i havent metered is the cdi switch box. Is there any readings on that to look for? Pretty expensive, id really like to make an educated diagnosis if possibly

Thanks if anyone can help
 

99yam40

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pick up proper peak volt meter or a DVA adapter to use with a regular meter to check the inputs and out puts of CDI
Intermittent problems can be hard to find, May be just a corroded connection in wiring/ground.
CDI is Capacitor Discharge Ignition ohming a capacitor may not be a reliable way of testing. voltage is

Primary is the input to coil
secondary is the high voltage output
 

rothfm

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Yea good call on the peak meter. Ive got more motors now that i ahould admit! About time i got one of these for sure

Will shop around for it or an adapter. At the moment all seems to at least have proper resistance. Pointing to cdi but will wait till i get a meter finally

Thanks
 

99yam40

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Adapter is less money, but you have to have another meter to go with it.
So it depends on if you have a good meter already and just need the DVA adapter

The analog peak meter needle will react faster than the digital readouts, so seeing a intermittent problem may be easier
 

rothfm

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Weird discovery: The CDI pages listing the 1997 Yammie 6hp, only show Stator Peak reading (100), The places on the chart for everything else just have a blank (Trigger, and CDI out). Whats that telling me? Not able to measure? Same in the Page from Yamaha I downloaded too.

This is a tuff one. Its in my heated garage....I can pull it and light a spark tester on each plug....Then the next pull, nothing. Any thoughts on that symptom?

Still persuing DVA and OEM manual.
 

rothfm

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Sorry to drag on this.....

Cdi got back to me with all readin specs resistance and peak volts.

I do have a meter but need to get the dva

One resistance reading that is off is the plug cap1 to plug cap2, of the dual coil. I read 8900ohms. Spec is about half that MAX

Does anyone think that would exhibit my symptom of spark on a pull or two, then no spark and repeats randomly?



I know.....get the dva already! :)
 
Last edited:

99yam40

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As I said intermittent problems usually are connection problems.
It could be in the coil or wiring .
hard to say, but your high reading kind of points in a direction

If you can get voltage reading at all positions when it sparks and when it will not , that should help narrow it down
 

rothfm

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Big thanks 99yam40...appreciated.

When I came home from work, and pulled sparking...after dinner, sparking, just now-Sparking! Wierd as I havent done anything. It is laying down on its side currently. Just for grins I will try some other positions tomorrow. If it continues to spark, I'll fuel it and try to start.

Still odd about the higher than expected across the wire leads.

I will follow up with findings once I know more, if it can help anyone else.
 

rothfm

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Update:
Summary---New to me 1997 (100bucks) didnt think it had spark-PO said it didnt. But eventually became solid after repeated testing.

Fired up the motor today...Hard to start, and wouldn't idle well, but it did run. I guess my spark issue is ok. (DVA and manual coming still).

I have to run the choke almost all they way out to keep it somewhat running. I bought a Yammy Fuel line connector to match the motor, and it plugs in real hard. I might direct connect the fuel line for testing purposes, in case I have a restriction. Really seems starved for Fuel.

No history with this little motor, So I might as well get a carb kit, Fuel pump diaphrams, The little fuel strainer, and impeller kit.

But I got a little Yammy 6hp 1997 for $100. Was worried at first, but it does run!
 
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