wanted jdm-74 TESTER

[JDT]

Nick I completed my reading assignment of 3784901.

My obsevations are that even though the name and the filing corporation are one in the same, the devise is not.
You will note that as discribed it requires additional hookups and has more components that the lil black box in question.

But the bascis are there. No doubt the box as built was based on this preliminary model.

Is there a subsequent filing that you discovered?

[nick80lf]

Not that I know of.

I believe that your earlier statement is correct. I believe that this box is just giving a visual indication of adequate voltage levels that are set by the pot. I think that if we knew what the "target voltages" are we could do the same tests with a "peak hold" DVM (or scope) and a home built load coil.

[JDT]

Again while never seeing the a genuine tester box nor the instructions I can only assume that the "tester coil" is just a know coil with the same load characterists as the actual external coil of the engine.
If you know you a have a good coil than you can use that as the load and take a voltage reading on the output of the CDI box.
With the all in one CDI/coil setup it is just a pass/fail/replace.

My readings in the past have been 90-200 volts for working systems. My DVM is not of bench quality and has a slow response(capture) time so I figure that is good enough if I get say 100 volts. In reality it may well be in the 400-500 volt range as in the reading assignment.

As for the internals I just use the open/short/close to spec ohm test.
As discussed in another topic, this does not include under load and temp increases that can make one pull his hair out.

One way of fixing a dead engine is to replace every component with new but that is expensive and some pieces are very scare.

[JDT]

So did Electro Specialties build the PrestoLite CDI's in the CCW's?

Could someone who has JDM-74A-6 Special Wiring Harness check and tell me if there is a component hiding under the shrink tubing?

Also any info printed on the load coil and simulator?

[TOYMECH]

I managed to find one of these testers and have with it:

1-Test Simulator - plugs into 115v AC outlet and has a momentary pushbutton switch on the other end. I'm assuming it has a cap in it to simulate the capacitor discharging..?

1-JDM74A-3 test harness (for Liquifire and Cyclone)

1-JDM74A-6 test harness

1-load coil

I did not get a manual with mine.

There are some other bits and pieces of harnesses with it as well which i think are part harnesses.

If i can be of help with photos of any of this, i would be glad to help out.

Todd - there are no markings on the Load coil - would a resistance spec be of help to you?
The only markings that the test simulator has on it is:

On the "115v end" the prongs are marked P and N

On the side it only gives a warning not to touch the plug terminals once the simulator was charged....I have to confess that i had to check this out and after having it plugged into the wall and touching one of the terminals to a piece of metal and leaving a gap on the other to the same piece of metal, it shot out a cool spark (YES, i amuse easily and refuse to grow up)...

I did some looking on Google and it looks that Electro-Specialties is still around under a bit of a different name:

http://www.esitest.com/index.html

Maybe they can be of some help...?

[JDT]

"On the side it only gives a warning not to touch the plug terminals once the simulator was charged....I have to confess that i had to check this out and after having it plugged into the wall and touching one of the terminals to a piece of metal and leaving a gap on the other to the same piece of metal, it shot out a cool spark (YES, i amuse easily and refuse to grow up)..."

Well you have tested the test equipmnet and know that it still works after all these years.
Electrolytic Caps do have a shelf life.

Yes, please throw an ohm meter on the loading coil.

So now who has the instruction booklet that can send me a scan?

[JDT]

Hey just for shits and giggles, charge up that Stimulator one more time and put your meter on the highest DC range and the leads on P&N.

You know what to do next. Than post your reading.

[jdrob]

OK Todd First you have a PM. I have the paperwork also(instructions) read the PM and lmk

[jdrob]

This was in my garage in a box of NOS ditch pickle parts.. I guess I need to be more observant !

[skoalmint]

Time out guys!!! Are we still talking about Testers or women.LOL!!!!!! ,I have to addmit they were both a shocking expierience,Just my past speaking out!!!! Brock

[JDT]

Rob I replied to your PM before looking at this post.

Some of my questions are now moot.

Thanks again.

[nick80lf]

Now I'm confused. Rob, why does your tester look different than the yamaha one that's on eBay? The picture in my liquifire manual looks like the Yamaha tester and is called m-74 tester, but so is yours?

Also, what is the simulator (that Greg likes so much) used for.....test the functionality of the tester? The liquifire service manual shows it but never describes what to do with it. Does it have a use on some other model?

[TOYMECH]

Todd,

Checked out the load coil for resistance and came up with 1.0 Ohms of resistance.
Charged up the Test simulator and found i had 115 VDC using a Fluke 77 meter. I checked outlet voltage that i plugged it into and got 121.5 VAC

Rob - I'm a tad confused as you have pictures of a Merc-O-Tronic CD tester. We had one in the shop where i worked as a Mercury Marine mechanic....

Ok, and just WHAT is a "Ditch Pickle".....

[TOYMECH]

So did Electro Specialties build the PrestoLite CDI's in the CCW's?

Could someone who has JDM-74A-6 Special Wiring Harness check and tell me if there is a component hiding under the shrink tubing?

Also any info printed on the load coil and simulator?

Todd, i had a look at my harness and there is nothing hiding under the shrink tubing...

Greg

[jdrob]

Ok, and just WHAT is a "Ditch Pickle".....

Greg a "ditch pickle" is a Skiroule sled. I not supposed to mention other brands of sleds on here other than JD Thats just slang we folks down south here use !

Now as far as the tester goes, I am not sure if it will work for what I need it to do, but I shipped it to Todd (JDT) to see if he can make heads or tails of it.
I am clueless when it comes to electrical stuff. I try and keep it simple: spark from 2 plugs,fuel, and compression(sometimes optional) and it should run !