modified cdi and cr 80 coil

[k.mah]

Can I ask what the difference is on what the original Jag and the modified cdi does?? Not very electronic savvy lol.

With the modified, you can run the same settings as the "jag" but you can also advance timing if you choose (27ohm resistor jumped with 390 bridged out of the circuit)

IMO, if you don't fully understand the timing settings, the modified might be a bit too much.....coming from the guy that blew a hole in his piston by having the wrong settings

 

[Toadmund]

That part, BT136-600E is a TRIAC, what you need to use is a(n) SCR.

I told the ebay vendor of the typo, calling it a SCR TRIAC. Gave me 40% off, I got a $1.58 refund!
WooHoo!
(Still not changed though)

 

[ivan H]

Hi, yeah, if u dont fully understand the jumper settings to select between the 2 variations u could easily over advance the timing. I have emailed the schematic for the stock Jag circuit & a simple vero board layout to a member & I'm pretty sure that he's going to draw them up on the computer &post them, I'll check back with him to make sure. If he's not I could email them to someone else to get posted, as I dont have a computer or know how to use one. Made on vero board & with quality components they are quite sturdy & I've made several for friends & none have failed. Cheers

 

[ivan H]

Oh, & in regaed to substituting SCR's, if u do, even tho the substituted SCR may have the right or higher voltage & current handling capacity, it'll most likely have a different gate threshold characteristic, which means it'll trigger into conducting at a different time. It may not be much, but it depends on how different the characterists are. Stick to the C106D. They are cheap as, common as & were the origonal part in the KDX CDI the circuit was adapted from. Cheers

 

[hsvmick]

ivan can i ask if this modified cdi unit have higher voltage and current handling capacity,then do you think it can run two coils from the unit to two spark plugs ,or would the current handling fall to great and little spark to both then ?

 

[ivan H]

To be honest, I'm really not sure. They do produce a hotter spark than the Chinese CDI/coil unit. I suppose the only way to know is to try it. Maybe if u could find a coil designed to fire 2 plugs,,, I know they exist but where u'd find I dont know. IIRC, there r 2 types of coils, rising field & falling field (maybe), so u'd need to be sure u have the correct type of coil. Apparently the CR80 coil gives the hottest spark of all the small MX types (very hot, will spark over something like a centimenter gap outside of the combustion chamber) so if u could find a twin plug coil with similar specs I dont see why it shouldnt work. I've always used the same coil off an old 500cc dirt bike wreck & it works really well. U could easily try parralleling 2 coils off the CDI to see how it goes. Good luck with & let us know how u go with. Cheers

 

[hsvmick]

thanks for your reply ,i used to use mick's cdi and cr80 coil before he sold it out to JAG ...I been playing around with a longer shaft to run two mag's but the magnetic fields are playing together, getting the thing to spark at the right time is a headache looked so cool and to my plan was then to run two mod jag cdi's retard a plug and avd one to the other plug .i was talking to Fred today and he has good ground and knowledge in how he runs two plugs with a 12volt battery gy6 scooter cdi with two coils and i think i will go this way cause i have had weeks of headache trying to come up with a two mag coil maybe still could but it is hard to know where it fires the second one being longer on the shaft maybe and the more rev's it gets worse anyway hope someday someone can nail this

 

[Toadmund]

Circuit diagram

Here is the Board Layout from the parts side.

SCR,C106D,4A,400V,TO-202AB CASE
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?freeText=C106D&langId=-1&storeId=10001&productId=160119&search_type=jamecoall&catalogId=10001&ddkey=http:StoreCatalogDrillDownView

It's stated in the modded jag clone diagram, that a 600v- 8a SCR is used but the c106d is rated 400v-4a, then your link to a part is the c106d1.

So which one is it?
A 600v-8a?
c106d?
c106d1?

Can I use this one instead?
5P4M 400v-5A
Compatable?

 

[ivan H]

Hi, I've always used the C106D SCR. Rated at 400V, 4A. This is more than enough for this application. Like, I used 250VAC rated charge caps & havent had a failure in several thousand kilometers on mine, plus I've built several for friends who havent had a failure, so voltage wise its fine. Current wise its so over rated for this application it doesnt warrant consideration. This SCR is the one that was used in the origonal KDX CDI, so it has all the correct opperating specifications, is cheap & commonly available. Use the C106D. Cheers

 

[ivan H]

Re: Waterproofing a mag?

It's stated in the modded jag clone diagram, that a 600v- 8a SCR is used but the c106d is rated 400v-4a, then your link to a part is the c106d1.

So which one is it?
A 600v-8a?
c106d?
c106d1?

Can I use this one instead?
5P4M 400v-5A
Compatable?

Any 400V (or more) SCR, if connected correctly & everything else being correct, will fire, but, as I have said b4, the Gate threshold characteristic will in all probability be different. This means that the CDI will fire at a different time. How different depends on how different that gate threshold characteristic is from that of the C106D's. The C106D is a very commonly used component, & they're cheap as chips. U'll get them over the counter at any electronics outlet. Cheers

 

[Scott.D.Lang]

Id like to thank you guys for doing this even though I will not be building my own. I would love to but it took me several hours to read this since most of it might as well been greek to me. That said from what I can understand I do like how you all have made a CDI set up that is more adjustable then anything else out there. Keep up the good work I look forword to see how you all do on more things like this in the future.

 

[soup325]

whoop whoop, I have spark. I will post some pics of my creation soon.

 

[ivan H]

Cool, now u can enjoy smooter running & higher reving motor, with better torque. I recently got an email from a guy I had sent a rough schematic & the layout I use for the stock Jag CDI. He is going to try & get them both drawn up on the computer & post them, hopefully at the very beginning of a new thread so people dont have to seach to find them. If he gets this done I will post some tips telling how people can fine tune them to their specific needs by simply changing the value of a resitor or adding another tantalum cap in the timing network. Cheers

 

[k.mah]

Cool, now u can enjoy smooter running & higher reving motor, with better torque. I recently got an email from a guy I had sent a rough schematic & the layout I use for the stock Jag CDI. He is going to try & get them both drawn up on the computer & post them, hopefully at the very beginning of a new thread so people dont have to seach to find them. If he gets this done I will post some tips telling how people can fine tune them to their specific needs by simply changing the value of a resitor or adding another tantalum cap in the timing network. Cheers

Gettin on it
just got busy with work/projects/work projects.

 

[soup325]

well, I haven't taken a photo of the bread board yet. this is my version of the CDI.

I have replaced the jumpers with single throw, double pole, 3 position switches. this was to take into account for jp4 and jp5.

I used an old 240V extension cord for the wiring. I striped the outer sheathing. Unsoldered the stock wires from the mag coil and rocker switch, so there was no potential voltage drops in the wires.

Note: the SBP rocker switch has to be reversed in order to take into account the new version of the circuit diagram. the off position becomes the on position. as the switch doesnt earth the red in the circuit anymore.

The bike runs very well now. peak power for me is around the 3000 - 4000rpm mark. very low vibrations. I love being able motor around at low rpm and not making lots of noise.

I dont have to use much choke either. I only have to use it when starting on a cold morning and I need to turn it off almost straightaway

Thanks Ivan and Dracothered

 

[ivan H]

Cool. They do make for a smoother running % torquier motor. Once we get a simple vero board layout up it should help more people who dont have electronic experiance to get 1 built. There isnt that much to them & they really do make a noticeable difference. Cheers

 

[wakhoma]

I .m noob here, please help me which ignition coil is the best for jaguar cdi ?, is it true this cdi can use with any ignition coil and it can work with all jumpers are taken out. Thanks

 

[ivan H]

Hi, if u build the stock Jag circuit it will run no problem with no jumpers attached, however, if u build the 2 in 1 unit that is shown schematically earlier in this thread, u will need to have jumpers 4 & 5 attached at all times as these 2 r used to select between the stock Jag circuit or a variation on the international model of the KDX. To make a stock Jag circuit using the 2 in 1 schematic is relatively easy. See jumper 4 selects either a 16 ohm or 27 ohm resistor to earth. U need the 16 ohm for the Jag circuit. It connects to the cathode (or k) on the SCR & earth. Leave the 27 ohm out, & jumper 4 & pins. Also, see jumper 5 bridges either a 100 ohm or a 390 ohm resistor, thus taking the bridged resistor out of circuit. U need to remove the 100 ohm resistor & jumper 5 & pins. Thats it. As for the coil, I think the CR80 coil gives the hotest spark, but almost any small MX coil will work. Cheers

 

[wakhoma]

hi Ivan H, do you mean when I use Modified CDI Schema of dracothered member, should attach 4&5 jumpers. Is it right?, sorry for my English.

 

[ivan H]

Hi, yes, that is correct, jumpers 4 & 5 must be attached at all times but be sure to properly understand their use to avoid advance/retard extremes. To select the stock Jag circuit u would place jumper 4 to select the 16 ohm resistor. Jumper 5 MUST then bridge (short) the 100 ohm resistor, thus taking it out of the circuit. Alternativly, to select the more advanced timing of the international variant of the KDX CDI, jumper 4 would be placed to select the 27 ohm resistor. Jumper 5 then MUST be placed to bridge (short) the 390 ohm resistor, thus taking it out of the circuit. Jumpers 1, 2 & 3 are left off the board when you start testing for best position. First test for low RPM setting of jumpers 1 & 2 by adding either jumper 1 or jumper 2 (not both, tho it wont hurt if u do) to find which gives best low RPM power. To test for jumper 3 is the same except you are looking for best high RPM performance. For a little more flexibility in high RPM adjustment, the 0.47uf capacitor that isnt on a jumper may also be put on a jumper to earth. Hope this all helps. Cheers