cicone

Member
Sep 29, 2003
310
0
Well, after exhausting all avenues, I've determined that my CDI bit the dust. Values don't match the revised table that Tedkxkdx supplied this forum. Looked at the detailed illustrations on Jaguars site and attempted the repair---not recommended. Very tight clearance between the box and circuit board(I accidentally shaved one edge of the board off) and that silicon with all the chips imbedded in it is a nightmare. So I'm doing the unthinkable---making my own circuitboard from scratch(Radio Shack kit--$15)and buying the components(about $10). If this works I'll let all know. As Gatorkdx will tell you, I'm a cheap ba$tard and saving $200, not to mention how fun and challenging the task, will be more fun than a barrell o' monkeys. This weekend will be fun, fun.
:yeehaw: Probably need a few beers too(12 pack $8 locally)!
 

skipro3

Mod Ban
Dec 14, 2002
902
0
But, but, but.....It will NEVER be a moto-x bike!!! :joke:

It always amazes me; the depth of involvement KDX owners are willing to go in order to advance their personal experiance into this motorcycle. Thanks in advance for keeping us updated.
 

cicone

Member
Sep 29, 2003
310
0
I'm not trying to make it a motocross bike . I just want it to run right. The CDI is bad. We'll see what happens.
 

m0rie

Member
Nov 18, 2002
469
0
cicone said:
I'm not trying to make it a motocross bike.

I think SkiPro was just trying to poke fun at the 2 page long "rear fender" thread from last week. If you get your homebrew CDI working i'd be interested in hearing how well it works etc. Keep up the work!

-Maurice
 

skipro3

Mod Ban
Dec 14, 2002
902
0
Trying?!? TRYING????? It was a very funny poke at the "rear fender" thread thank you very much.
Anyway cicone, I admire you and your tenacity to repair or improve on your KDX. I'm sure once you have the basic CDI down, there will be others here who will then take that design and experiment with it. Keep us informed with your progress.
 

BJH

Member
Nov 9, 2003
126
0
skipro3 said:
Trying?!? TRYING????? It was a very funny poke at the "rear fender" thread thank you very much.

That was a fun thread...Now you and Okie be good boys, run along and go blow enough cash on "fiddys" to buy a KDX. :laugh: let the games begin!

Let us know how the CDI comes along
 

cicone

Member
Sep 29, 2003
310
0
Maybe I spoke too fast about not recommending this project! Spoke w/someone who works with circuitboards and the products used to seal/insulate them. There are potent solvents available to eat the silicone off the board, but surprisingly, soaking in plain old rubbing alcohol makes the removal quite easy. I will try to post some pic's later today.
Radio Shack should have an SCR---according to Jag and my good friend, that's the most likely part to fail---the only moving part, if you will. The large yellow capacitor was destroyed in the procees---not sure if I can buy one locally. Also looks as though I didn't hacksaw enough of the board to render it useless. :cool: So far, so good!
 

cicone

Member
Sep 29, 2003
310
0
pic's---the carnage---the board
 

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cicone

Member
Sep 29, 2003
310
0
CDI Update---Just ordered parts yesterday from Mouser and expect by Friday. Jag's notes on the subject appear to be very accurrate. He has a '89 model. There was a minor difference on the circuitboard with my '90 edition. The resistor which he refers to as the "pull down" is a 15 ohm 1/2 watt on my bike---not a 16 ohm. I also was not able to procure a 1.7K thermistor anywhere, so I'll have to try using the 1K in series w/680 ohm resistor as he suggests. Also ordered 2K thermistors to try w/22K resistor, which Jag also suggests. If you look at my CDI photo, you'll see 5 diodes on the board. Jaguar suggests replacing them all w/1A 400v. I've decided to replace the 3 black/blue diodes normal ones of that value. The large black diode located just left of the SCR will be replaced with a 3A 1000v since it pulses current to the ignition coil(for reliability). Also upgraded the rating on the 4.7 25v cap to 50v for the same reason. The little red diode on the other side of the board appears to be of the small signal type and is encased in glass, not plastic. That will be replaced with a 1A 400v of the smaller variety. Will try to make a couple prototypes and test this weekend. Awaiting some technical assistance from a major player in the auto CDI arena---since they don't make motorcycle CDI's(yet, anyway), they have been more than receptive on technical issues. :cool: If anyone wants a parts list, email me and I'll forward it. BTW, there's only about $5 worth of electronics on the board---no where near the $225 they want for a replacement. I ordered a ton 'o stuff so I could experiment and always have at least two good boards---total cost $10.36 plus shipping.
 
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Pwgsx

Member
Oct 10, 2004
54
0
Hey, What was ur bike doing that let you know that the cdi was the problem?? Mine is bogging after it is run for about 5 min.?? LEt me knwo about that board, I might have you make me one : )
 

cicone

Member
Sep 29, 2003
310
0
removed the SCR from the board last night along with the leads from the big yellow cap. interestingly---the SCR which Jag suggests to replace w/8A 600v---is a NEC part number
2P4M, which is 2A 600v(4A rms)---perhaps the upgrade is more reliable??? i don't know squat about electronics, though
i've learned more in the past two weeks than my entire lifetime. hopefully this beast will be running this weekend. parts expected via ups any time this morning! ;)
 

canyncarvr

~SPONSOR~
Oct 14, 1999
4,005
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In every case I've worked with failed SCRs a large part of the problem was a spec that was on the low side. There is almost always a good reason to stick in more 'A's.

Looking forward to hearing how great it turned out.

What about that mylar cap? I don't see that referenced in your parts list..well except for the capacitor reference involving ohms and watts....which is obviously not a capacitor. Did you come up with one'a those?
 

cicone

Member
Sep 29, 2003
310
0
canyncarvr said:
What about that mylar cap? I don't see that referenced in your parts list..well except for the capacitor reference involving ohms and watts....which is obviously not a capacitor. Did you come up with one'a those?

My mistake---typo---I meant to say the 15ohm 1/2 watt "pull down" resistor. Sorry about that. :clue: It's the big one coded: brown, green, black, gold.

To answer your question---yes. One is the 4.7uf 25v that I upgraded to 50 volt and the other is a 1.5uf 250v metallized polyester---mouser.com part #23MA515.

Is that the one you're talking about? There's a picture of it with the remains of the CDI box.
 
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canyncarvr

~SPONSOR~
Oct 14, 1999
4,005
0
The big yellow one.

My terminology is probably wrong. The yellow one is the polyized metal one? ;) ...seems they are usually hi-freq jobs.

Are you going to pot this goody after you know it works?
 

cicone

Member
Sep 29, 2003
310
0
canyncarvr said:
The big yellow one.

My terminology is probably wrong. The yellow one is the polyized metal one? ;) ...seems they are usually hi-freq jobs.

Are you going to pot this goody after you know it works?
I think the metal poly and mylar are synonymous. Yeah, plan to pot it---have to find some non conductive silicone. This whole thing has been an adventure.
 

canyncarvr

~SPONSOR~
Oct 14, 1999
4,005
0
What do you plan to use for the bullet connectors?

I have never found the nice, long, pliable weather resistant type of covers as used on the kdx (and lots of other places).

Maybe you got those from Mouser, too?
 

cicone

Member
Sep 29, 2003
310
0
canyncarvr said:
What do you plan to use for the bullet connectors?

I have never found the nice, long, pliable weather resistant type of covers as used on the kdx (and lots of other places).

Maybe you got those from Mouser, too?
say what? no, seriously---going to rehab the old board w/ the original wires. then make another board or two from scratch with slightly different parameters. THEN i'll have to figure out where to get those little thingies, but I think it wouldn't be a problem getting them at our local bike salvage place---should be plenty of them there!
 

cicone

Member
Sep 29, 2003
310
0
skipro3 said:
The local U-Haul sells those bullet connectors here for trailer hook-ups. Maybe those will work.

i'll check it out! Got the board completely desoldered. Ready to replace the components. Having some issues regarding using flux to prepare the contacts. Don't know anything about this stuff. Any feedback would be appreciated,

Thanks,
 

kmccune

2-Strokes forever
LIFETIME SPONSOR
Jul 3, 1999
2,726
1
Just go to radio shack and get rosin core solder, heat the contacts with your soldering iron and touch the rosin core solder to the contact, making sure that is it is on the board that you don't close up the hole for the electronic component. Place the component through the hole AFTER bending the leads to fit the holes and reheat, apply more solder. Done! Carefull with the soldering iron so you don't burn the traces off the board.
 

skipro3

Mod Ban
Dec 14, 2002
902
0
Don't use flux made for things like radiator soldering, or copper pipe sweating. That stuff is too corrosive. Silver solder is a bit more expensive but you do end up with a more rugged connection. It's available at radio shack. It contains no lead, or at least that is why I'm told I have to use it at work over regular 60/40 lead solder. You may want to use a flux remover after the solder job is complete and before potting it. I have some potting kits that I use when sealing up cable splice jobs that are exposed to outdoors. They are available at most electronic supply stores but I'm not sure radio shack has them. I'd be willing to dig around and find a left over one from my stash if you can't find one and send your way if you need it.
 

cicone

Member
Sep 29, 2003
310
0
skipro3 said:
Don't use flux made for things like radiator soldering, or copper pipe sweating. That stuff is too corrosive. Silver solder is a bit more expensive but you do end up with a more rugged connection. It's available at radio shack. It contains no lead, or at least that is why I'm told I have to use it at work over regular 60/40 lead solder. You may want to use a flux remover after the solder job is complete and before potting it. I have some potting kits that I use when sealing up cable splice jobs that are exposed to outdoors. They are available at most electronic supply stores but I'm not sure radio shack has them. I'd be willing to dig around and find a left over one from my stash if you can't find one and send your way if you need it.
Thanks for the offer---thinking i'll just pot it with blue rtv(if it's non conductive) and little stones that you would put in an aquarium. Talked with a guy who's company sells the potting stuff and that's what he recommended. I think the comp. was epoxies.com---based in Rhode Island. He said the reason for the "stones" in the silicone was partly to deter reverse engineering, but primarily for heat dissipation---said mixing sand with the potting would do the same thing. Ain't this fun!!
 

skipro3

Mod Ban
Dec 14, 2002
902
0
The RTV may take a bit of time to set up and cure fully. I don't know if it is conductive in it's uncured state or not. If you use sand as filler for the RTV, run a magnet through it to pick up any iron that might be incorporated. The aquarium gravel should be good if you go that route as well.
I've also seen clear resin at art supply stores. It's sometimes used to encapsulate a flower or some such item and turning it into a paperweight. The neat thing about that is it's clear. That might be an advantage, if you use something like, say tin foil as a homemade box, then remove the foil when cured.
Great job your doing for us all here, thanks!
 

cicone

Member
Sep 29, 2003
310
0
Just got all the new components soldered. Will check tomorrow and, if it works, will post a picture before potting.
 

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