KDXRIDER.NET

UPDATE: Switches found and ordered!

MoonStomper wrote: 08:16 am Feb 04 2022 Setbacks are the name of the game, can’t tell you how often this has happened to me. Anymore I just expect things to be wrong when I order stuff. When I was a kid I remember being sooo excited to order something out of Boys Life magazine and then to get it and be disappointed with it’s form or function. … why I never ordered the hovercraft kit!

QUESTION… so the pink cdi that guy did has two tiny switches in his non-potted design. How are you going to set up your switches? My son’s 2008 KTM 144SX had an adjustable cdi that you had to pull the tank, find the harness, unplug one wire, and then plug in another. This softened the hit and gave better soft terrain traction. I liked it softer, but Henry liked it in ‘wild mode’ better so I bought some tiny red push button switches on Amazon and wired one in that I mounted under the tank for easy access. Problem was, it was kind of hard to tell which mode you were really in without hammering the bike. So it would be nice for this interface to allow you to just look at it and know.

Does this make sense? So what do you have in mind for mode changes? Let me know if I can help you model some practical ideas from a user-interface perspective. Something bar-mounted would be interesting to consider.

My design won't be adjustable on the fly. That changes the design quite bit as that only allows a two curve system and the curves would have to be predefined which goes against what my design philosophy for this CDI is based on. My design philosophy is to make it easy for anyone to get as close as possible to the perfect ignition timing setup, for your particular bike, without going to a fully digital/computer setup.

Now, on to how it will be switched... I just finally found the switches this morning (different design than I originally intended) that should work so I can give an answer on that. It will use two rotary dip switches that you'll be able to change with a pocket sized small flat blade screwdriver. There will be no cover to remove or anything like that. They will project just out of the potting compound while the electronic components will be 100% sealed away from dust and moisture. Oh, the switches have changed the IP water/dust rating from an IP68 to an IP67 which is still more than enough for a dirt bike. Anyway, depending on where you mount the CDI, you'll have to pull a side panel or the seat to gain access unless you come up with a creative location to allow easier access.

Now, down the road I might create a Version 2, possibly, to make a two curve, on the fly, switched CDI so you have the Sun and Rain mode type setup some newer bikes have. It all depends on if there would be enough of a demand for it and somehow figure out what would be the two best curves to incorporate in to it. That last one is kind of tough as what is best for one bike won't necessarily be the best for another.

Ahhh I see. So you can dial it finitely between fully advanced and fully retarded timing. Then through testing on your particular bike with its particular setup (with snorkel or w/out airbox lid, wood or Rev pipe, oem reeds or Radvalve) you can independently find the sweetspot setting for traction in wet or power for dry.

Perfect!

This must be close to the type of switch you mean? It would be nice to be able to mount it where you can reach it with your screwdriver without removing the seat. Maybe a longish pigtail could facilitate this?

How would the two rotary switches function? Like one would control the curve down low and one at higher RPM?

MoonStomper wrote: 02:37 pm Feb 04 2022 Ahhh I see. So you can dial it finitely between fully advanced and fully retarded timing. Then through testing on your particular bike with its particular setup (with snorkel or w/out airbox lid, wood or Rev pipe, oem reeds or Radvalve) you can independently find the sweetspot setting for traction in wet or power for dry.

Perfect!

This must be close to the type of switch you mean? It would be nice to be able to mount it where you can reach it with your screwdriver without removing the seat. Maybe a longish pigtail could facilitate this?

1B66F4FA-A41B-4C02-86A1-DDCCC135951B.jpeg

That pic is the style of switch I will be using. Yes, it will allow you to dial it in depending on the mods you have, from bone stock to a fully ported, squished, bored out beast. However, it wont get as many curves as there are positions on the switches as that would create a very complex and crowded circuit board. Plus, the way those rotary switches are wired internally are a little different than a standard SPST on-off switch. Depending on the position it can connect up to four points simultaneously or none at all. Each switch will give you four different timing curve plots. Switch #1 will affect the bottom to mid-range predominately but will affect the top as well. Switch #2 will only affect the mid to top end timing.

I was planning on making the wire length longer than factory to facilitate the end user more options in the placement of the CDI but think I'm going to keep it very close to stock now. I don't want to get crazy with the length and then you have to tie up a big rat's nest of wiring that is hanging right above the shock and expansion chamber. Of course, the connectors are all types easily found anywhere so it would be easy to create a pigtail any length you desire pretty easy. You could even mount it behind your front headlight if you wished!

Slick_Nick wrote: 05:08 pm Feb 04 2022 How would the two rotary switches function? Like one would control the curve down low and one at higher RPM?

Pretty much. Only the bottom-mid switch will also affect the top somewhat. For that reason when dialing in the ignition you will always start with switch #1 first, find what you like there, and then start adjusting switch #2. Once you've done that you're done and don't need to do anything again. Well, unless you just want to play with it some more or change it for specific conditions.

Hope you can get these trick CDIs made and the performance is as good as the Jaguar. Good luck and once you do I'll buy two of them.

UPDATE: My switches finally made it just a few minutes ago. I only bought six as I wanted to make sure they work before I order the full lot. They are quite a bit more expensive than I was hoping for but it's worth it if they do the job. I will say, they are tiny!

Are you going to ‘pot’ them in a small case? They really are tiny!

MoonStomper wrote: 07:31 pm Feb 10 2022 Are you going to ‘pot’ them in a small case? They really are tiny!

Yes, in the smallest case I could find that would fit everything inside without going to custom made ($$$) housings. 2x2x1.5"

Thinking I will make a pigtail for it so I can place it where I can access it easily for testing. Leaving the original where it is for ‘just in case’.

I’m stoked you’re doing this! Count me in for one as well!
Something I hadn’t been able to find a solid answer on: Can you run full advance on the stator with 91 octane without det in most cases? I see where you touched on this earlier in the thread and it sounds like with good jetting you can run full advance on 91+?
What Im stoked most about is actually being able to utilize 100*+ octane with your CDI + advance on the stator!

My prototype was first run this evening. There is definitely more advance as it wanted to kick back just a little. That's actually a good sign that there is enough advance dialed in to the base curve. Gotta finish it up with potting it and then it's ready to hit the trail. First ride report will be this coming weekend.

Awesome! I’m so stoked to hear how it works out!

Thanks, man! I was pretty freakin happy to hear the bike fire up. No matter all the planning, double checking, etc, the stress doesn't go away until you here it actually work!

Excited to hear how she tests!

So am I!!

Well, met up with Slick_Nick and his wife today. We hung out for about 2 hours and I had a great time. It was so cool finally meeting my online buddy for the first time and talking everything KDX! His wife was super understanding about our insanity and is an awesome lady in her own right. Hope you guys make it back soon and we can do some riding!

Reason I'm posting this here is because Nick is the recipient of my very first adjustable CDI I was willing to send out. The potting hasn't even fully cured on it yet! Still not happy I couldn't find the wiring in the color/stripe configuration I wanted but it is a complete and working unit. Hopefully this encourages him to get out and ride his KDX some more. Besides, Nick, you gotta get your lady back out on the trails as well so go ride!

Me on the left, Nick on the right

Even though many of us have never met one another in person, there’s a real feeling of community here on KDXRider. While I’ve never officially “met” SS109 before today, it feels like I’ve known him since I first joined this forum, 13 years ago. He’s been a wealth of information, and his passion for the KDX is, in my opinion, unmatched.

It was an absolute pleasure to chat with you today my man! I could sit and talk KDX for hours upon hours! I’m honoured to be the recipient of the genuine, bonified, serial number 001 adjustable CDI! I promise I will put it through its paces, including some cold weather testing. Can’t wait to get this thing back to the north and see how far we can push it!

The CDI unit looks amazing. It feels well built, you can tell that it’s made from quality components. The switches are potted in nicely, I can’t wait to get it mounted and start tinkering with the various settings!

That’s a stoutly built unit, a KDX-worthy looking piece for sure! Neat that you guys could get together, I know Slick Nick enjoyed seeing the sun again!

Yep, that CDI so new that I haven't even gotten the label for them printed up nor completed the installation/tuning instructions yet! I wanted for him to just transport it to Canada instead of shipping it. This way I know he got it and didn't pay any crazy fees on top of it. BTW, working on the installation and tuning sheet right now. I'll make the electronic version available here online and I also plan to ship out a sheet with every CDI going forward. In the near future I also probably do a video covering both the installation and tuning.

It is very cool that you guys got to meet up. I do have some bad news, though. Neither of you is close to being as pretty as that CDI. It looks terrific! Thanks for making it.