Do SR models have a different cdi box?

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Roadhazardguy
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Do SR models have a different cdi box?

Post by Roadhazardguy »

Just wondering if the SR models have a different CDI box with a different timing curve then our bikes since they're designed for street use.
Last edited by Roadhazardguy on 11:04 pm May 16 2013, edited 1 time in total.
Tony
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1980 KZ 1300
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Do SR models have a different cdi box?

Post by Dodger »

Roadhazardguy wrote:Just wondering if the SR models have a different CD box with a different timing curve then our bikes since they're designed for street use.
Yes they do!

I have the Australian version of a 1989 KDX200SR - it's called a KDX200F1 - and according to the owners handbook the ignition timing is 17°BTDC @ 1300 rpm ~ 22° BTDC @ 4000 rpm.

The E series ignition timing according to the service manual is fixed at 21° BTDC @ 6000 rpm.

I have fitted the E series CDI to my bike (I had to extend the wiring as the CDI is mounted on top of the air box lid on my bike) but when I checked the timing of both CDI's by strobe light, I couldn't see any real difference in the advance or timing!

It's probably psychological, but I think that my bike goes a bit better now with the E series CDI!

Cheers
Last edited by Dodger on 02:32 am May 17 2013, edited 1 time in total.
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Do SR models have a different cdi box?

Post by Julien D »

Dodger wrote:
Roadhazardguy wrote:Just wondering if the SR models have a different CD box with a different timing curve then our bikes since they're designed for street use.
Yes they do!

I have the Australian version of a 1989 KDX200SR - it's called a KDX200F1 - and according to the owners handbook the ignition timing is 17°BTDC @ 1300 rpm ~ 22° BTDC @ 4000 rpm.

The E series ignition timing according to the service manual is fixed at 21° BTDC @ 6000 rpm.

I have fitted the E series CDI to my bike (I had to extend the wiring as the CDI is mounted on top of the air box lid on my bike) but when I checked the timing of both CDI's by strobe light, I couldn't see any real difference in the advance or timing!

It's probably psychological, but I think that my goes a bit better now with the E series CDI!

Cheers

Thank you for that post, good info there!
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Roadhazardguy
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Re: Do SR models have a different cdi box?

Post by Roadhazardguy »

Thanks for the info! I got to wondering this because I want to convert my ATK over to Sumo/Street use, and while doing so I want to get rid of the motoplat stator on my ATK and use a bosch stator from a Can-Am. Then I can rewind it for for better lighting and ignition, so i'm trying to figure out what the best CDI box would be to use. I figured the timing curve might be a deciding factor while picking a box and its looking more and more like it should be, any ideas?
Tony
1988 KDX 200
1980 KD 80
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1984 RM 500
1980 KZ 1300
2008 SM450R
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Re: Do SR models have a different cdi box?

Post by Dodger »

Roadhazardguy wrote:Thanks for the info! I got to wondering this because I want to convert my ATK over to Sumo/Street use, and while doing so I want to get rid of the motoplat stator on my ATK and use a bosch stator from a Can-Am. Then I can rewind it for for better lighting and ignition, so i'm trying to figure out what the best CDI box would be to use. I figured the timing curve might be a deciding factor while picking a box and its looking more and more like it should be, any ideas?
Sorry but I'm afraid I don't have any ideas!

I've never swapped a CDI from one make of bike to another.

Good luck with your project.

Cheers
I may be old, I may be slow, but hey I'm still getting my leg over - a dirt bike!
Roadhazardguy
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Re: Do SR models have a different cdi box?

Post by Roadhazardguy »

Does anyone have an SR box they want to sell me or something with similar timing curve. That is pretty darn close to what I need if not just a few degrees higher at the bottom with about the same curve.

Edit: Never-mind that wouldn't be right, I misread it. It needs to be pretty much backwards from that. That is a really weird timing curve for a 2 stroke from everything ive seen, and that''s probably why you felt an improvement when you switched.
Tony
1988 KDX 200
1980 KD 80
1989 ATK 406
1984 RM 500
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Do SR models have a different cdi box?

Post by Jaguar »

There are basically two types of CDIs, one that uses a trigger voltage and one that doesn't. The KDX doesn't. If you want a KDX CDI then you can buy one from me. Here is my page about it: http://www.dragonfly75.com/moto/KDXCDI.html
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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Re: Do SR models have a different cdi box?

Post by KDXsg »

Yes you can the E and SR 200 CDI is interchangeable. only difference is the extra wiring on the sr model cdi.
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