DVA Voltage specs needed

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daselbee

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I have a Suzuki DT20 , 1986 model. CAn someone post the DVA measurements on the trigger wires to the pack?

I have a black (GND), a black with red stripe, and a white with red stripe feeding the pack.

Also, should this CDI ignition generate a spark that will jump the normal 7/16 in gap on a spark tester?
Should it maybe jump a smaller gap?

Any help appreciated. I have no access to any manuals.....

Thanks.
 
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daselbee

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Re: DVA Voltage specs needed

Thank you very much. I had no idea that Yamaha and Suzuki were the same....

Gives me something to do today!

Thanks again.
 
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daselbee

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Re: DVA Voltage specs needed

Wooopppsss.....no match here on that chart.
Not by year, not by wire colors, and these small YAmis seem to use surface gap plugs. Not the same here on this DT20.

Here is what I have:

I am getting 150 V DVA on the black/red, and 0.5v DVA on the white/red.

I think the 150v is OK...that is in line with alot of other engines, but I question the 0.5v. That is apparently the trigger voltage, and I wonder if it is high enough. Newer J/E engines use 0.6v trigger, but I am seeing Yamis using from 2.5v to 6v for the trigger value.

I will measure the resistance of that trigger coil today.

Trouble is...I got no manual!!!!

Makes it tough to guess at this stuff......
 
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daselbee

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Re: DVA Voltage specs needed

Bump up...no one has a suzuki DT-20 1986 manual to consult for these values?
 
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schematic

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Re: DVA Voltage specs needed

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daselbee

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Re: DVA Voltage specs needed

Thanks, but these Yamaha charts are not matching what I have here. One glaring mis-match is the last column, showing no plug gap...which means surface gap plugs. I have regular side ground electrode plugs.

Additionally, there is NO SEPARATE ignition coil. The CDI and coil is all in one unit, so there is no way to measure the primary of the ignition coil, for example.
With the CDI in my hand, I have 4 wires.....ground, kill, trigger coil and power coil. Then there are the two plug leads out. Very simple, but at 300 bucks......gotta be sure.

I have the Suz manual coming from Brown's Point.....should be here Wed., and I will post (just for kicks) the values I find in the manual.

I just don't want to shotgun parts. I want to be able to debug this down to the exact bad component.

Thanks again.
 
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schematic

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Re: DVA Voltage specs needed

neither 40hp Yamaha or 40hp Suzuki use surface gap plugs. The column at the end of the chart isn't "gap". Your motor should be similar if not identical to a Yamaha C40.
Quit likely, the primary of the ignition coil can be measured from "kill" to "ground". I have a wiring diagram if needed.

Good luck
 
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daselbee

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Re: DVA Voltage specs needed

Ah quite right about the gap vs cap reading error on my part.

But...I posted on a DT-20 Suzuki. Why reference 40 hp Yami?

Is there some equivalence that I am missing....I don't see anything.....?

Book's coming...it will be here tomorrow.
 
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schematic

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Re: DVA Voltage specs needed

sorry daselbee, I must have slipped and hit my head!
 
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daselbee

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Re: DVA Voltage specs needed

Well.....for those following this...
Crap!!!!

I got the factory Suzuki manual for this 1986 DT20, and went looking for the DVA voltages I needed.

Not there. All they give is the resistance of the coils, and a couple of wire colors/electrical diagrams.

This is very frustrating.

I called Brown's Point and told them the issue...that the manual specifically did not tell me what I needed to know.
The sales guy was actually pretty helpful. He was knowledgeable about DVA measurements, and told me that way back when, they didn't really have a DVA spec, and the only thing they used was resistance values.

Ok....so I asked him to return any electrical parts I purchased, return them in unopened packaging....nope. Not gonna do it....

OK....so I asked him.....which part sells most? The CDI module or the pulser coil (those are Suzuki's terms), and he said the pulser coil by far.

So I guess I will shotgun the pulser coil...50 bucks....and see.

I will post...the pulser coil (trigger) is hitting at 0.5vDVA at pull start speed with no plugs in the engine. No spark.
Unplugged, it is hitting at about 20vDVA at the same speed.
The power coil...the one that energizes the ignition...is hitting 150vDVA at the same speed. This seems right to me.

But I question the 0.5v on the trigger. Should it be higher or not?

Anyone with practical experience on what I should be seeing is certainly encouraged to post back....
 
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daselbee

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Re: DVA Voltage specs needed

Thanks 99yam....

That has some great info in it. Cut and paste that bad boy and saved it....

I like your "looking at other brands might give some insight into what I should be seeing" idea.
I have done just that. I see other engines with the trigger pulse hitting between 2 to 6 volts DVA, like the Yamaha chart up above. But I also see some with the trigger pulse hitting 0.6v DVA.

The manual front pages is a sort of generic DT-20, DT-25, DT-30 catch-all tech manual....
But, the back of the book has model specific info. So, I am getting good matching info from the DT-20 section.
But it still does not give any DVA voltages, just resistances.
And, it specifically says to use a Suzuki CDI pack tester. It gives the part number of the tester. It shows a pic of this tester, and it is a box that plugs into the wall outlet, and apparently generates pulses into the CDI unit under test, which you have connected up, spark plug leads and all. It then has a gap on the box, and if the spark jumps the gap, CDI unit is good.

Unless an old-timer Suzuki mechanic knows from experience what I should be seeing DVA voltage-wise, I will just have to shotgun the pulser coil first (50 bucks) then the CDI unit (309 bucks).
Another key reason for me to get the pulser coil first is the fact that Brown's Point sales guy said the pulser coils are big sellers, and they keep them in stock. He also said the CDI packs are "hardened" (his word) and rarely ever blew. Insight.

Don't know what else to do.

I do have an old motor junkyard near here. If they have a DT 20, 25, 30 I might go down there and spin it to see what it measures.
Assuming the ignition is good on the junk one.

Ah well. The owner wants to go fishing!!!!
 
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