a vs b style cdi box

[lwb140]

hello so the 340/s looks to use the type a cdi box with round plugs , so to go to the type b what has to change and are there advantages to it . im considering buying a new b type cdi box for 40 bucks but not sure if it will work with the original stator and trigger coil ,and ignition coils , could i use a 340/22 stator and trigger , will it fit in the 340/s motor? been gonna pull a /22 motor apart to see but im sure many of you know this off hand , also will i need to [could i ] use new coils from dennis kirk they arent terribly expensive and i dont have any used ones either , just thinking if i put all new parts on this sled it may save a ton of frustration later

[JDT]

Wade I have used the aftermarket boxes on both A and B stators with the same results.
The $40 box is half price from the going rate.
I can't attest to compatibility with a 340S as I have never had one, but I think they are the same.
Maybe Brian Linder can share some light on this.

[400brian]

The 340/S does not use the A or B box. It and the 295/S uses an earlier box, with 2 pairs of wires and one single, plus the coil and ground wires.

As far as I know, you can splice any plug you want to run, onto a Prestolite box and it should work.

The /22 engine will have a very similar stator, if not identical.

I just bought a re-wound stator over the weekend, and it gives me exactly the same ohm readings that the core I turned in did!

[lwb140]

thats awesome on the stator im glad there is someone else in the world that does the same kind of things as me !! i hope it at least works though thanks for the info on the cdis planning to put a new aftermarket on it ,hoping to eliminate a headache or two thanks wade

[harleysportster]

I just bought a re-wound stator over the weekend, and it gives me exactly the same ohm readings that the core I turned in did!

Brian,
I have read of others sending out their stator also and have had bad results. I even emailed Scott Hewlett (Hewtec cdi) and he couldn't find anyone to successfully rewind a Prestolite Stator due to the very thin wires.
As far CDI compatability, later style B with the rectangle plugs, or the JD round plug type should replace the 295/S, 340/S style. Follow the wiring diagram in the post of "Diagnosing CDI problems" in the FAQ section.
The $ 40.00 dollar aftermarket CDI box seems cheap but many members have experienced early failures. The top brand of aftermarkets is the Fire Plug CDI by Hewtec.

[ICCSF 108]

The 340/S does not use the A or B box. It and the 295/S uses an earlier box, with 2 pairs of wires and one single, plus the coil and ground wires.

Brian, I thought the " A " boxes were the ones like the 295/S & 340/S used meaning the Male/Female Plug at the box type where as the " B " boxes were either the Rectangular or Round plug with wire extensions type boxes?? ( see Hewtec web site picture section ) http://www.hewtechelectronics.com/images/A-STYLE.JPG Showing this as an " A " style box

Kenny

[400brian]

Kenny

I'd thought that Scott referred to the square plug as an "A" and the round plug as the "B".

However, after checking out his website, I see I'm in error. OK, we'll call the 295?s and 340/S CDI boxes "A"s
The rest are "B"s.

[400brian]

I just bought a re-wound stator over the weekend, and it gives me exactly the same ohm readings that the core I turned in did!

Brian,
I have read of others sending out their stator also and have had bad results. I even emailed Scott Hewlett (Hewtec cdi) and he couldn't find anyone to successfully rewind a Prestolite Stator due to the very thin wires.
As far CDI compatability, later style B with the rectangle plugs, or the JD round plug type should replace the 295/S, 340/S style. Follow the wiring diagram in the post of "Diagnosing CDI problems" in the FAQ section.
The $ 40.00 dollar aftermarket CDI box seems cheap but many members have experienced early failures. The top brand of aftermarkets is the Fire Plug CDI by Hewtec.

No argument from me. I went with the Image CDI because I could keep my original looking box. ( and they are $200 ea, )
As it stands, out of 4 Prestolite stators I have ( including one rewound ), not a one of them falls into the ohm range Scott says they need to be in to fire his CDI box. I'm at a loss. I may really have to convert the SOB to point ignition!

[JDT]

The low speed winding seams to fail more than the high speed from my experience.

Do you guys think that a failed winding can take out an otherwise working cdi box?

I have seen many original Presolite boxes corroded and expanded(swelled) and of course dead.

Seams that the pot metal was not up to par with the enviroment.

The aftermarket boxes look to be better as far as the housing goes.
I have not had one fail ... yet.

[ICCSF 108]

We had the low speed go out on our Dator back in 77 If you could pull it over fast enough you could get it started & it would run but we always had the Idle set way up so that is probably why?? Anyway it DIDN'T burn out the CDI but then again that was when everything was fairly New..

Brian, I can't believe that you are even considering going to points? it seems to me there is a lot more to go wrong with them, 2 points, 2 condensers, internal coil & windings etc.
Why not convert it to the newer stator & trigger, I guess is there really a difference between the AM53177 Trigger & AM53179 Stator , & the AM53753/AM54173 Triggers & AM53755/AM54174 Stators, other than the plug ends?? Why not try a newer Stator & trigger ( GOOD used of course ) & splice in the 340/S plug ends off a old Stator & trigger Assembly that you know doesn't work?? Hell someone has to be the Guinea Pig & the snow is a ways away so YOU have plenty of time for R&D

Just my $.0765 worth
Kenny

[400brian]

Rainville has an NOS stator. I asked him to do an ohm test on it and report back.

Does anyone have one that tests over 2500 ohms on the low speed windings?

I just want to know if they ever do.

As far as converting to points....at this point in time, I'm not so sure they aren't more reliable. Campbell has done it, he's the evil influence

[ICCSF 108]

Brian, If your willing to walk me through it on the phone, like maybe tomorrow night, I can ck a few of mine USED 340/S & NOS of the newer style.. Just let me know about what time so I'll have a chance to get my Poo-Poo together..

Kenny

[400brian]

Kenny

It's real easy. There are 12 poles on the stator. 3 are noticeably different, those are the ignition windings. On the older stators, the 2 wires coming out will be 1-black and 1-white. Newer stators will have 1-blue, 1-yellow.

The white or yellow wire is the low speed winding, the black or blue is the high.
You connect one test lead to a wire, the other to the frame of the stator ( ground ).

On the 340s stator, the white wire ( should be female at the plug ) should indicate between 2000 and 3000 ohms. The black wire ( should be male ) should indicate between 30 - 100 ohms

There are other tests as well, but this is what we've been talking about.

[ICCSF 108]

OK here's what I found, for the 295/S & 340/S tore down motors that I have, I sure as hell don't have enough used stators,
2- have wires broken at the stator itself, Do you think these could have new wires solder on??
1- seems to have the low speed out,
1- engine must have been converted to the newer style rectangular plug stator & trigger ( not sure about the flywheel )
the last one I could find check's out like this,
Black wire is 50.9 ohm with the meter set on 200 ohm
White wire is 2.62 ohm with the meter set on 20K
So I assume that means it's at 2620 ohm or is it at 2062 ohm??

Kenny

[JDT]

Your good to go Kenny.