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GK76A which CDI ???

Posted: Fri Jan 23, 2015 1:32 pm
by powerplay
Hi All,

I have a 1993 GK76A 400 Vin number GK76A-107736 which has a CDI problem!
The last owner had trouble as in lost spark so found a replacement unit which he fitted which then gave him spark but even with fuel and spark the bike would not run.
I have taken over and found that the old CDI and the new one have different part numbers.
So what i need to find out is what options I have for replacement CDI units.
The old one's part number was 32900-35D30 followed by BB7260 is that the only one I can use as I don't know which model I have ?
Any help would be great.

Thanks

Re: GK76A which CDI ???

Posted: Fri Jan 23, 2015 10:44 pm
by Variablevalves suck
32900-35D30 is off a P model.
What number was on the old one? Think a 32900-35D31 would work as the S has the same pickup/trigger but the earlier L M and N models use different cd's and different triggers.
If you have a early cdi and can get a matching trigger you are ok.

Re: GK76A which CDI ???

Posted: Sun Jan 25, 2015 6:45 am
by SevenThreeSeven
Here's a image from the Bandit 400 side of things. Might help you to understand what you're up against, at least with respect to the question of why a CDI that can make spark might not be timed properly to run the engine.

Image

Re: GK76A which CDI ???

Posted: Sun Jan 25, 2015 6:40 pm
by Variablevalves suck
Yes the 53 hp bikes have different triggers than the 58 hp models so you can swap both cdi and trigger but not one part.

Re: GK76A which CDI ???

Posted: Mon Jan 26, 2015 9:43 am
by powerplay
Thanks for your replies...
Would the CDI unit from a GSF 400 Bandit be correct then?
Or have you any 1993 CDI's laying around anyone!? :pray:

Re: GK76A which CDI ???

Posted: Wed Jan 28, 2015 3:29 pm
by SevenThreeSeven
Or have you any 1993 CDI's laying around anyone!?
Old GSXR400 and Bandit 400 CDIs can be refurbished.

There are two things that go wrong inside these CDIs: the capacitors age and dry out and are sometimes ruined by overvoltage from automobile jump-starting attempts, and the other thing that goes wrong is failure of the ignition drivers (a.k.a. "NPN Silicon Darlington switching transistors").

There are 5 Capacitors and 2 ignition drivers.

The good news is that these items are easily replaced by somebody who's good with a soldering iron. The capacitors can by identified and replaced by reading the ratings off of them and the ignition drivers can be replaced with TIP150 Darlington Transistors.

After you have the CDIs refurbished you can try them in your bike to see which one is the correct box for your bike.

Re: GK76A which CDI ???

Posted: Wed Feb 18, 2015 10:01 am
by powerplay
Thanks for the info...all I need now is someone who can do this work as I am not having much luck finding anyone!
Does anyone have a number please :grin: ?

Re: GK76A which CDI ???

Posted: Wed Feb 18, 2015 1:10 pm
by Variablevalves suck
if you have two different cdis it may be easier to get a pick up.
can you post up both the part numbers listed on them and i will see what i can do.

Re: GK76A which CDI ???

Posted: Wed Feb 18, 2015 7:21 pm
by SevenThreeSeven
Also, another factor you have to make sure to get right is the pin-out of the connector plugs.

You can see in the picture I posted earlier in this thread that even the very simple situation that exists within the Bandit 400 CDIs (it's either one or the other) actually uses two different pin-out configurations. On the smaller plug (the one that comes from the trigger wheel pulse generator) pins numbered 7 and 8 are reversed between the 1991-92 models and the 1993 models.

Can't believe you're unable to find a good electrician to refurbish your CDIs. It's not that tough of a job, even a moderately skilled guy could do it.

Re: GK76A which CDI ???

Posted: Wed Feb 18, 2015 9:33 pm
by Variablevalves suck
As I stands one of the cdis is sparking but not running.
I'm thinking this is due to wrong trigger timing so cheapest fix is the correct trigger, wires can't be reversed as it wouldn't spark.
This all hinges on the non sparkling cdi definitely being the correct one and the sparking cdi being wrong.
If the sparking cdi wrong then a second hand trigger is about £20 and a puller about £10.
If the sparking cdi is correct them the problem is elsewhere maybe carbs.