Author Topic: Testing Coils  (Read 15109 times)

Offline PitterB4

  • Administrator
  • Board Homesteader!
  • *****
  • Posts: 3698
Testing Coils
« on: March 11, 2005, 09:04:15 PM »
Good info saved from the old board again...

Fresh Roadkill!
Posts: 3
(9/11/04 11:14 am)

  testing the coils
 hi everyone.. I am having some problems with my bandit.. cylinger #1 and 4 are not firing!

how do I check the coild ( I am hoping that it is only the coil..)

I did a search and didn't come up with the answer..


I hope it's not the cdi..
Hall Monitor
Posts: 5558
(9/11/04 1:55 pm)

   Re: testing the coils
 Can you swap coils between 1/4 and 2/3?
The only other way would be to try a new coil.
Before you spend the money for a new coil, be sure the wires supplying the coil are not causing the problem.
Paul W
WWBOC #684
Camano Is. WA, USA
Highway Hamburger!
Posts: 61
(9/11/04 4:26 pm)

   Re: testing the coils
 use a multi-meter to check the resistance across the primary and secondary coils. you shouldn't need to remove the coil pack from the bike to resistance test it.

- the primary coil resistance should fall within the 2.5 - 3.8 ohms range

- the secondary coil resistance should fall within the 30 - 50 k-ohms range

the primary coil is tested where the wires from the wire harness plug into the coil pack. make sure you match the (+) terminal of the multi-meter to the (+) terminal of the coil pack.

the secondary coil is tested plug cap to plug cap.

if the coils check out, plug everything back in and check for spark at the spark plug:

pull the cap off the #1 plug, pull the plug out of the head, push the cap onto the plug, and ground one of the plug's side electrodes against the cam cover. I'd wear gloves and use a pair of insulated pliers to hold the assembly from the plug cap.

bump the motor over with the starter button and you should see some sparks jumping across the plug electrodes. if the coil pack checked out and you still get no sparks, you probably have a bad connection in the wire harness (or a reversed polarity connection at the coil pack).

Edited by: tankmonkey at: 9/11/04 4:36 pm
Fresh Roadkill!
Posts: 4
(9/12/04 3:35 pm)

  Re: testing the coils
 well the coils tested ok..
both 3.1 ohms primary
both 24K ohms secondary

1 and 4 don't spark 2 and 3 do

looks like it's the cdi.. I checked it for blown component parts and no visual malfunctions

thanks guys

I guess it will going going out for repair unless I can find a donor??
Highway Hamburger!
Posts: 62
(9/12/04 6:51 pm)

   Re: testing the coils
 have you checked the continuity of the wire harness between the cdi box and the problem coil pack, and also between the coil pack and ground?

if there isn't a break in either of those wires, I'd agree that your ignitor box needs to be checked.
Fresh Roadkill!
Posts: 5
(9/12/04 11:45 pm)

  Re: testing the coils
 soory I forgot to mention a I swapped the coils and had the same result, I also tested for voltage @ the coild and was 12 volts..

but I will check for continuty tomorrow.. I want to exhaust all potential problems before I replace/repair the black box..
thansk again
'93 Bandit 400 - SOLD
'98 Honda F3 Track Bike - SOLD
'98 Kawi ZX-6R Street Bike - SOLD
'00 Gary Fisher Kaitai
'09 Bianchi Via Nirone 7