coils swap

[albertinhouston]

Can I use a the coils from any other Suzuki bike as a direct swap?

Has anyone went to the newer gsxr style of individual coils?

[Chris H]

Yes yes and yes.
You can use any coil that has the same ohm reading as the oe one.

You can fit stick coils but you will have to use the short cbr ones, even then they stick up along way as the b4 is very shallow.

You have to make your own loom for th as the cbr loom is wrong.
There are plenty of posts on the net showing how to rewire them.

I used them on my VC bandit and only removed them because the VC oil feed had to be removed every time I wanted to take a plug out.

Make sure the water drain holes are clear if using sticks or you will fook them.

[albertinhouston]

Do u know which suzuki bike are direct swap. The bike i just bought had some other coils. But they are NOT Bandit 400.  I dont have a base line to compare the ohm too
Thanks

[greg737]

the issue that matters is the Dwell timing of the CDI. 

Dwell is how long the CDI grounds the primary winding inside the coil (one coil for cylinder 1 and 4, one coil for cylinder 2 and 3) before releasing, which causes the field in the primary coil to collapse which causes the secondary winding to also peak and collapse on a grand scale, which fires the spark plug.  The Ohm reading of the primary winding of a coil gives you a hint as to how long the proper Dwell period should be.

If the Dwell period of the Bandit's CDI (which you can't change) is too long for the coils they will overheat and burn out.  If the CDI's Dwell period is too short for the coils you choose to use you'll get a weak spark.

I have no idea what the Dwell setting(s) of the Bandit CDI actually are, but based on the math involved in this high-revving engine I'd be willing to bet it's in the 2.5 to 2.8 millisecond range.

The math for the Bandit engine looks like this:
14,000 engine rotations per minute (60 seconds) and there are 1000 milliseconds in a second.  So 60,000 milliseconds in a minute divided by 14,000 equals 4.286 ms per 360 degrees of engine rotation.  That's all the time that the CDI has to charge and fire the spark plugs (because the CDI uses a "wasted spark" ignition scheme each spark plug fires every 360 degrees)

[albertinhouston]

I do appreciate ur post. But im just too to see if i can just get some .... Lets say Katana coils and use them on the bandit.  Or maybe there is another bike i can get a set from

[albertinhouston]

Here is what I know so far.
I have no spark from either coil. They are not factory coils.
I have power going to the coils (I think its the orange wires)
I'm going to test the coils today.

here is my question.... what tells the coils to make the actual spark? I would think it'll be the ECU but not positive.
 meaning...
if the coils test good then what will be the next thing to try?

[Chris H]

Is the bike a Jap import.
Some things to check will be.

General condition of the loom connectors.


 signal generator, comes out of the L/H engine cover and should have a ohm reading of around 100 ohms.

Gear sensor, near front sprocket.

Safety devices like stand switch (should still start be not if gear sensor is bad) and clutch switch if fitted.

Kill switch.

[albertinhouston]

Its a standard US market bike.
It got dark on me yesterday so I only had about 15 min to tinker with the bike.

Do you happen to know what the stock coil range is?

[albertinhouston]

I finally got 5 minutes to check the coils.
If I did it correctly, Pulse generator showed good.
Primary side of the coil would show a reading
secondary side wouldn't show anything at all....

I have a set of 09 GSXR COP I'm going to try to wire in this weekend.

[Chris H]

cop,s simply wire 2 each side in series.
you need to get the + and - the correct way around though.
there are plenty of how to on the net if you google. 

[albertinhouston]

Hopefully I can get it right. lol.

 I have a complete(junk) wire harness off the 09. so I'm going to get the connectors and wire from there.
 Im "HOPEING it MIIIIIGHT be wired correctly on the GSXR so all I have to do is add power to the removed harness. I'm sure it wont work out that way though...

[albertinhouston]

Let me ask you this...
Can I connect the bandit wires(orange /white) to one coil just to see if I get any spark?
I don't need it to run I just want to see if I can get spark from it.

[Chris H]

Its ages since I did mine so I'm a little dusty on the full set up but you basically connect two cops in series to each of your low tension supplies
You need to get them the right way around or it won't work and you need to connect two coils because at 1.5 ohms per cop if not you are doubling your amps in the circuit which might not do the cdi any favours.


Strangely when in series you don't get three ohms but 2.8 if I remember, must be some induction going on in the coil but I had no trouble running it like this.

The cop loom is not wired in series so you have to chop it and re wire which is a pain as the wires are very fine, I used the connectors from the cops and then simply wires spades to fit the bandit wires on the other end.

Think the cop connectors are sumito or something like that and be bought new from good motorsports shops.

[albertinhouston]

 I tried it and I did get spark from the coils. AT the very least it tells me the coils I have a bad. :)
The spark seemed week though. But at least I was able to prove it's the coils that are bad. I'll work on the wiring this week. my focus will be cleaning the carbs for this week. :-/

[albertinhouston]

If i under stand it correctly... I will take the harness positve and connect to cyl.1 postive at the COP. Then take the negative from CYL 1 and connet it to cyl. 4 positive COP. Ill take the neg. From the COP and connect it to the neg from the harness.

 Thats what i have and im getting what seems like a weak spark. And the motor is backfiring.
I just had a thought.... In my reply.  Maybe i have my 1&4. Powered to the 2&3 power supply this sould explain the back fire.... Lets see.
Edit.... Well it wasnt that lol