Kr1 Cdi Vs kr1s

Dodgy Kips motor? CDI? battery? diode? reg/rect? its all gobbledygook to me but some people understand it ask tham a question here
Post Reply
dave32
Heavy Smoker
Posts: 472
Joined: Sun Oct 24, 2010 10:15 pm

Kr1 Cdi Vs kr1s

Post by dave32 »

Does anyone know if there is any different between the 2 CDI's?
Ive run both on a B2 and cant tell any difference.
Pretty sure they were supposed to be different though?
Cheers
Dave
mgtkr1
Premix Junkie
Posts: 1402
Joined: Tue Feb 13, 2007 10:04 pm

Post by mgtkr1 »

i think, though not sure but i beleive the kr1s cdi revs on a bit more, poss 500rpm. mj will know coz he dynoed a ike yrs ago testing various oxes kr1/1s. also i the the ignition curve is very slightly different ut again this could be border-dash. i distincly remember there been chuff all in it though. irc one gave a bit better results but more than likely because the condition of the connectors/circuit board was better rather than owt else. if you look up team sparrow it refers to it on there somewhere.
User avatar
JanBros
Avgas Sniffer
Posts: 3306
Joined: Wed Jul 26, 2006 11:50 pm
Location: the land of Francorchamps

Post by JanBros »

Dave, I've ran both on a tuned KR1S and I found out that the KR1 was no good for it. the bike ran, but lost about 2.000 rev's at top. wouldn't go above +/- 10.000 (if I remember correctly, it's been over ten years), while with the S I could go to 12.000 and above (but I always stopped at 12).
My ultimate goal is to die young as late as possible !
dave32
Heavy Smoker
Posts: 472
Joined: Sun Oct 24, 2010 10:15 pm

Post by dave32 »

Thanks for the replys guys,
So it seems in Jan's case there was a large difference and MJ's case there wasnt much if anything in it. ](*,)
Maybe its a bit like there Generators,some last forever others needed rewinding after a few years,maybe there's good and bad CDI's.
Ive got a few spare so its probably a case of just fit each one and see what works best.
I remember reading about a mod some race team did that increased the current dumped through the CDI,but it didnt mention how this was done.
Apparently the kR responds well to closing the plugs and the pick up coil airgap up,again ive tried but there was no noticeable change.
Cheers
Dave
alimorg
Site Admin
Posts: 1382
Joined: Tue Jul 25, 2006 11:34 am
Location: South Wales (Old)
Contact:

Post by alimorg »

Pretty sure one of them opens the power valves 500rpm before the other think its the KR-1 that open up first - although I could be mistaken
Cheers
AL
"A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. " - Douglas Adams
dave32
Heavy Smoker
Posts: 472
Joined: Sun Oct 24, 2010 10:15 pm

Post by dave32 »

Yep that would make sense as it would suit the higher exhaust port of the S if it opened later,cheers Ali.
Ive always wondered if/how you could mod the servo so it could open later to suit a tuned for more top end motor,im sure its possible but i aint no leccie wizard,anyone tried it?
Cheers,think i will have a look through my CDI's and give em a go now you got me curious! :D
Dave
mgtkr1
Premix Junkie
Posts: 1402
Joined: Tue Feb 13, 2007 10:04 pm

Post by mgtkr1 »

alimorg, yes that sound familiar. like you said dave i think theres a variation between them. some better than others and by now i suspect there arent many duff boxes around. that mod to the ignition was irc found by the great jr or at least something to do with jr. in fact i think jr got it from another supersport team but was told to keep schtum.. was back when then did the ''walking the dog'' features on the kr1s as a racer.
User avatar
scooble
Premix Junkie
Posts: 1549
Joined: Thu Jul 27, 2006 12:47 pm
Location: West Sussex
Contact:

Post by scooble »

I'm not an electronics expert, but I would of thought that if your were to dump more current into the CDI you would need a higher rated capacitor.
I also heard a rumour that the Sean Emmett team were using two CDI boxes, but dunno if thats true or not.
Would switching to a non wasted spark system yield any benefits too?
TwoStroke Institute
Oil Injector
Posts: 505
Joined: Sat Jul 05, 2008 2:17 pm

Post by TwoStroke Institute »

scooble wrote: Would switching to a non wasted spark system yield any benefits too?
Open the bonnet of a modern car and see if they have 1 coil or a coil per cylinder?

Just get a Zeeltronic or Ignitech and be done with it ](*,)
crochet & croquet
mgtkr1
Premix Junkie
Posts: 1402
Joined: Tue Feb 13, 2007 10:04 pm

Post by mgtkr1 »

easiest, most reliable and all round better option is to go ignitech or zeel. theres more to it than that though, satisfaction from doin it yer sen. also its fun to fiddle and experiment. thats why we race/track/road ride the kr. otherwise we would buy any year r6 and not need to fiddle. its a question thats been asked many times, how to modify the std box. i for one have asked but it remains almost mythical, the ss400 kr1s igniter box mod. doubling up sounds familiar but given that times are hard and kr igniter boxes are thin on the ground i havent the balls to faff.
KR-1R
Premix Junkie
Posts: 1587
Joined: Wed May 16, 2007 2:24 am

KR-1 vs KR-1s ignition curves CDI

Post by KR-1R »

http://kr-1s.co.uk/forum/viewtopic.php? ... c&start=45
SATARNS curve...
Image

MJ43 measured standard 1287 (KR-1S)ignition...
Image

Standard KR-1 vs KR-1s ignition (CDI) curves
Image

CDI Ignition identification
21119-1234 JDM and World KR-1 (B)
21119-1255 Feb 1988 F3 Formula3 Kit CDI source: 1988 Kit manual Oct2015
21119-1275 JDM KR-1S, KR-1R CDI (C/D)
21119-1278 KR-1S/R F3 kit (1989) source: 1989 Kit manual Feb2019
21119-1279 KR-1S SP kit ignitor CDI http://blogs.yahoo.co.jp/okatasi2004/GA ... 64865&no=2
21119-1287 World KR-1S (C)

MJ43 hacks the curve with an oscilloscope
viewtopic.php?t=5308
Last edited by KR-1R on Tue Sep 13, 2016 1:54 am, edited 4 times in total.
User avatar
scooble
Premix Junkie
Posts: 1549
Joined: Thu Jul 27, 2006 12:47 pm
Location: West Sussex
Contact:

Post by scooble »

can someone please remind me which box cycles the powervalves quickly when turning on, and which box cycles them slowly?
User avatar
Mark66
Light Smoker
Posts: 37
Joined: Mon Jul 11, 2011 12:44 am
Location: Glasgow, Scotland

Post by Mark66 »

Hi guys .I'm relatively new to this and am prepared to be contradicted. The KR1 CDI moves the KIPS valves for the shorter time. Putting the KR1S CDI on a KR1 wouldn't make much difference as it's ignition curve is designed to work with the barrels/exhausts/KIPS of the KR1S. Seems bad ignition can be the result of various problems on this bike ranging from dodgy stator windings and pickups to simple bad connections. There are some seriously good aftermarket ignition/charging system out there but I can't afford them and I like a challenge . I've recently purchased 2 of these little wonders (introductions and pics to follow) and just love the info on this site . Keep it up boys.
Old Age Petrolhead
Gonzo355
Smoker
Posts: 87
Joined: Sun Apr 24, 2011 5:24 pm
Location: somerset

Post by Gonzo355 »

I have both types.
The 1st cycles the valves slowly and opens them at 8000 and revs to about 10500.
The 2nd one cycles valves faster and opens at 8500 and revs to about 12000 this i think is the s one.
The 2nd one also seems more "ready" to go -more advanced? but feels like it needs more fuel kr1s jets may help??.Both run on a b2 with s pipes
User avatar
JanBros
Avgas Sniffer
Posts: 3306
Joined: Wed Jul 26, 2006 11:50 pm
Location: the land of Francorchamps

Post by JanBros »

Gonzo355 wrote:I have both types.
The 1st cycles the valves slowly and opens them at 8000 and revs to about 10500.
The 2nd one cycles valves faster and opens at 8500 and revs to about 12000 this i think is the s one.
The 2nd one also seems more "ready" to go -more advanced? but feels like it needs more fuel kr1s jets may help??.Both run on a b2 with s pipes
that's what I experienced to, but aparently I was the only one :? Up until now :D
My ultimate goal is to die young as late as possible !
Post Reply