Coil Physical Size Question

[Joe Nardy]

My Katana has Andrews coils and wires but came with what were supposed to be the OEM coils and wires. I compared them this evening and found that the supposedly OEM coils have different mounting hole spacing than the mounting holes on the bike. The bike holes measure about 88mm and the coils measure about 100mm. The guy I bought the Kat from also had a '78 GS1000 and I'm thinking maybe he sent me the wrong coils. The part numbers are different and it looks like the '78 GS1000 coils mount from below while the Kat coils mount from the top. If anyone has coils laying around and could take some measurements I would appreciate the help. Also, here's a pic of the supposedly OEM coils. Please let me know if these look familiar to you.




Thanks,
Joe

[Guest]

Ohm them out. Should be five for the points.

[Nessism]

Make that 4.

[Joe Nardy]

Ohm them out. Should be five for the points.

Make that 4.

Good point (no pun intended) guys......now which is it? Four or Five?

[koolaid_kid]

It's a moving target, Joe. 4-5 Ohms is the spec, IIRC.
For an electronic ignition, it will be lower than 4 Ohms.
By the color and the epoxied wires, they do appear to be Suzuki coils.

[gert du prez]

If you would ever use coils where the mounting holes are a bit different from these on your bike, make sure the bolts do not touch the power inlet.
Have made that mistake on a set of new coils (green dyna) on wires where I did not install an inline fuse...

please...don't ask...

[Nessism]

FSM states GS1000 coils are 4 ohms. Of course you can expect some tolerance on that.

The GS1000 coils use 14mm plugs, and the 1100E/S coils take smaller 12mm plugs. Also, the 1100 spark plug caps are all long style, but the 1000 used two long and two short.

[Joe Nardy]

Coils measure 2.9 and 3.1 ohms.......

[rustybronco]

I'll try to measure the coils off my 1000 after I get home this evening.

[ptexotik]

FWIW, '82 1100 Kat (asia import) has orig coils looking exactly like that, but mounting holes 90mm center - center

[rustybronco]

1978 GS1000 100mm c-to-c.

[Joe Nardy]

1978 GS1000 100mm c-to-c.

Thank you Dale. Now, should the coils for that bike be 3 ohms?

Joe

[Guest]

Thank you Dale. Now, should the coils for that bike be 3 ohms?

Joe

No, 4-5
Guy gave you an off set for an electronic ignition.

[rustybronco]

I just looked at two GS1000 online shop manuals. The first one said the coil's primary resistance should be between 2 and 6Ω and the second one said approximately 4Ω.

[rustybronco]

Joe, do we know how accurate your DVOM's calibration is?