CDI Box Compatability

[upbeck]

Hello All - I'm hoping that one of you has a good understanding related to compatability with CDI's and Ignition coils between liquifires: '77 340 and an '80 440:

I have a '77 Liquifire 340/23 LC (Liquid Cooled Kioritz) with a bad CDI.

The original CDI was a Prestolite ElectroMAG.

On bad advice (a cross-reference listing on a web site), I purchased a CDI on ebay from a 1980 440 Liquifire. Now, I see that the wiring is not wire-for-wire compatible.

The one from ebay (LF 440) is a Kokusan Denski (Japanese).

Since I am quite comforable with cutting and splicing wires and understand electronic circuit theory related to CDI's in general, I am wondering if my mistake can be salvaged?

Is a retro-fit possible?

I'd appreciate any help you can provide.

Thanks!

[harleysportster]

Hello,
Welcome aboard. My understanding is that NO, they are not compatible. To start with, the triggering circuit would require that you exchange the inner stator and flywheel components as well and they are 2 different structures, such as size and mounting.
There were several styles of the Prestolite CDI boxes. By your discription, yours should have round plug connectors. That style CDI would be interchangeable with both the 77/78 JD Cyclone and Liquifire regardless of engine size. If you have the rectangle plug connector, a CDI from a 76 Cyclone would work. Before you throw your original away, follow the cdi diagnostic procedure located in the FAQ section:

http://www.jdsleds.com/community/viewto ... ?f=5&t=289
NOS CDI's and coils do show up on Ebay. Aftermarket CDI components are available. I would recommend using a Hewtec CDI. It is a direct plug-in and has a warranty. Many members have used some of the other brands and they fail early on.
Good luck,
Harley

[JDT]

Harley is correct 100%. But all is not lost. The box you purchased has value and can be resold or traded.

My experience with the Presolite CDI systems is that the low/high speed pickup coils on the stators fail just as often as the CDI boxes on the CCW engines. So check this carefully before you by a new CDI.

There is a NEW aftermarket CDI box that is correct for your engine on Ebay right now with a bid of $41.00 offered by troutcreeksales.
Pickup coils can be found new and used also.

[upbeck]

Thanks Guys for the links and the ebay lead -

JDT - I couldn't find the new CDI on Troutcreeksales. What's the item number?

I'll "ohm-out" my coils today.

Thanks again for the info. This is the second post string that I have created - the first since the forum changed. My first was for my other project - a "300" with a loud exhaust.

I both cases, it has been great getting such good help from the folks here.

Thanks Again,

Jim

[harleysportster]

There is a NEW aftermarket CDI box that is correct for your engine on Ebay right now with a bid of $41.00 offered by troutcreeksales.
Pickup coils can be found new and used also.

I believe this is what JDT was referring to. This is only correct if you have the retangle conector plug.
http://cgi.ebay.com/Kohler-Mercury-Twis ... 286.c0.m14

[upbeck]

Thanks Harley -

MIne has two round connectors..... I'll keep looking since mine also is for a Kioritz motor.

[upbeck]

On the other hand, I'm not affraid of making something work if all that's needed is cutting and splicing ..... back to my original question about electrical compatability.

[harleysportster]

On the other hand, I'm not affraid of making something work if all that's needed is cutting and splicing ..... back to my original question about electrical compatability.

The early Kohler engines used the same cdi. If you had the rectangle connector and found the round style, then yes I would say cut and splice but I wouldn't cut / slice the retangle type into the round unless that was the only source left. The round style was an improved version over the retangle type.

[upbeck]

Hello Guys -

I stepped through harley's checkout process and got a surprise: the Low Speed Coil is open (expected 2.7k Ω). Both Trigger coils and the High Speed coils matched the specs.

The lighting coil was a little high (.8 vs. .2 Ω) but I assume that I am seeing some contact resistance.

So, my focus has changed.

Should I plan on replacing anything else while I'm in there?

[harleysportster]

Hello Guys -

I stepped through harley's checkout process and got a surprise: the Low Speed Coil is open (expected 2.7k Ω). Both Trigger coils and the High Speed coils matched the specs.

The lighting coil was a little high (.8 vs. .2 Ω) but I assume that I am seeing some contact resistance.

So, my focus has changed.

Should I plan on replacing anything else while I'm in there?

Dave,
Double check the low speed windings, most times you get some type of resistance but it could still be open. Regardless, if the ohms for the low speed windings are not within 10% + or - of 2.7K, then the low speed windings have developed a short.
Now the bad, the stator assembly is getting hard to find and no one has successfully rewound the windings. You could search around the salvage yards, pick up a junk motor with good igintion or Evil-bay:
Here is a NOS stator for the rectangle plug connector. It would work by cutting / splicing the wires.
http://cgi.ebay.com/ebaymotors/Vintage- ... ccessories

[upbeck]

Harley -

Ouch ... $150 .... for a used part .... my project just got more expensive and more complicated.

Please clarify the relationship between the references to "B" style and the retangular connector.

The Hewtech print that you have pointed me to shows a rectangular connector that it says is a "B". The table on that print has an "A" and "B" column. The wire colors that match my stator are the colors listed in the "B" column.

I'm guessing that my ROUND stator connectors are just a distraction .... since my wire colors match the "B" style, then I need to buy a "B" stator.

Am I understanding this?

[upbeck]

Upon further review .... I see that $150 would get me a new one.

This still hurts

Jim

[JDT]

Greg Stebnor (sp) was selling NOS stators for $50 last year. He may still have some.

Other members may have one to spare also.

I agree that $150 is a little rich.

[harleysportster]

Harley -

Ouch ... $150 .... for a used part .... my project just got more expensive and more complicated.

Please clarify the relationship between the references to "B" style and the retangular connector.

The Hewtech print that you have pointed me to shows a rectangular connector that it says is a "B". The table on that print has an "A" and "B" column. The wire colors that match my stator are the colors listed in the "B" column.

I'm guessing that my ROUND stator connectors are just a distraction .... since my wire colors match the "B" style, then I need to buy a "B" stator.

Am I understanding this?

The " B " style refers to the rectangle type connector
Prestolite switched to the round plug connector in late '76
Both types use the same colors / wiring configuration
Unless you are disperate, hold out for a cheaper, correct stator for your engine.

[upbeck]

Thanks for the advice - I'll take it. As bad as our weather is, snow is not in the forcast.