Which coils interchange between models?

[Spikus]

I'm completely new to this, and just traded a pistol for a 79 GS425 with 4700 miles. It needs a coil, and most of the stock coils on ebay look the same but are for GS750s and 1000s according to the posts. Are all these coils interchangeable, or should I be looking for an aftermarket set of coils?

Thanks in advance,
Scott

[Steve]

You will need a coil that is specifically for a Suzuki twin, as it will have just one lead to the spark plug.

All the coils for the four-cylinder bikes have two leads each, and no, they won't work right if you simply cut off one lead.

.

[chef1366]

You will need a coil that is specifically for a Suzuki twin, as it will have just one lead to the spark plug.

All the coils for the four-cylinder bikes have two leads each, and no, they won't work right if you simply cut off one lead.

.

Out of curiosity why not?

[Steve]

Out of curiosity why not?

Because you need a complete circuit with two wires.

Pretty much the same idea as having two wires going to the battery. Cut one of them off, it won't work so well.

On the single-wire coil for the twins, one of the 'wires' is internally connected to complete the circuit.

.

[Spikus]

Thanks for this info. Would a coil for a GS400 or 450 work then? Since coils for any of the twins seem harder to find, are there any good options for aftermarket coils?

[tkent02]

I would think coils for any Japanese twin would work?

[80GS1000]

http://www.z1enterprises.com/ListItems.aspx?name=Electrical&description=&category=01010402020203000000

Take a look at the Dyna coils and call Jeff at Z1 to determine the best ones for your bike. I would think the green coils would be best, but don't want to lead you astray.

FWIW, I installed Dyna green coils on my bike and the difference from the new to old coils is like night and day - bike starts up much more easily and idles more smoothly too from the fatter spark.

[salty_monk]

The KLR650 coils should work for you I would think... (if they will fit in the space and the lead will reach the plug).

Just buy two of them. I picked one up recently for about $25 as a spare.

If you are on points you *may* have to put a resistor inline to stop the points from being degraded too quickly.

[Spikus]

Thanks for the tip 80GS! I talked for about 1/2 hour this morning with Jeff and he was extremely helpful. I'm going to go home tonight and check on a couple of things on my stock coils, then call him back tomorrow and probably order a pair. Jeff was great, and I see a lot of phone calls to him in the future as I learn all this as I go.