Ignition coils test?

[Guest]

hi I am new here and I need help,i am building a 1979gs550l and the coils on it were toast and instead of buying new ones I bought two used ones, how can I test them, I have seen videos that show using a multimeter at 200 ohms ,i tested them and I get no reading at al l .

[tom203]

From Basscliff's site

"With the coil plug connectors disconnected, use an ohm meter and measure the resistance of both windings on each of the coils. Exact resistance measurements are not too important, but continuity of the windings close to the approximate resistance values given indicates that the coils are in good condition. It must be noted that it is possible for the coils to only show up a fault when at higher operating temperatures, but this does not happen frequently.
Ignition coil resistance:
Between the two HT plug caps of the same coil, secondary HT winding, approximately 30 - 35 K ohm
Between the orange/white and white on the first coil and orange/white and black/yellow on the second coil, primary winding, approximately 2-5 ohm. If this test is within limits you likely have two good coils."

if you unscrew plug caps from a coil, you should measure about 12000 ohms plug wire to plug wire.
Make sure you understand your multimeter scales.

[vanguard]

I did that and I got nothing , no reading at all . So I guess I have four bad coils.

[tom203]

I did that and I got nothing , no reading at all . So I guess I have four bad coils.

The chances of having four bad coils is highly unlikely- I suspect you are having multimeter Reading problems.

[vanguard]

The chances of having four bad coils is highly unlikely- I suspect you are having multimeter Reading problems.

Yes sir you are right , I was not getting a good connection I got 3.9 on one and 4.0 on the other. So I have to install them tomorrow.

[jbird7262]

I recieved some coils from another GS member, tested the primary sides and got 4.5-4.9 on both coils, but I did not get a reading on any of the ohm scales 200-2000K for the plug wires (wire to wire), made sure I was making contact with metalic screw that holds the resistor. As I was moving the probes around the caps they were crumbling.

[tom203]

Remove the plug caps and then measure plug wire to plug wire on each coil- should be around 12000 ohms.( Make sure you understand your meter ranges.)The caps are tricky to measure over as they corroded and crumble, so get new ones- maybe $4 each

[trucker]

I recieved some coils from another GS member, tested the primary sides and got 4.5-4.9 on both coils, but I did not get a reading on any of the ohm scales 200-2000K for the plug wires (wire to wire), made sure I was making contact with metalic screw that holds the resistor. As I was moving the probes around the caps they were crumbling.

I have the same problem with my coils I have 4 coils I get a 4.5 to a 5.0 on the test to the wires. When I test from the wire to spark plug wire I get no reading on all 4. I thought and still think I have bad coil but then I tested my igniter thinking maybe that was bad and I thought it was as I got no spark on 2 and 3 plugs cuz I was thinking there was no way I had 4 bad coils so I bought a used igniter off eBay and still no luck. What is the chances of having 4 bad coils and 2 bad igniter.

[Brendan W]

I have the same problem with my coils I have 4 coils I get a 4.5 to a 5.0 on the test to the wires. When I test from the wire to spark plug wire I get no reading on all 4. I thought and still think I have bad coil but then I tested my igniter thinking maybe that was bad and I thought it was as I got no spark on 2 and 3 plugs cuz I was thinking there was no way I had 4 bad coils so I bought a used igniter off eBay and still no luck. What is the chances of having 4 bad coils and 2 bad igniter.

Very low to zero. The common element is the meter. How old is the battery?

[trucker]

Very low to zero. The common element is the meter. How old is the battery?

Battery on the bike is old not sure how old but old it hold 12V though the meter is only like a year old maybe I can buy a new battery

[Brendan W]

Battery on the bike is old not sure how old but old it hold 12V though the meter is only like a year old maybe I can buy a new battery

Worth a try although I'd expect a lot longer than that from a meter battery.

[jbird7262]

Recieved these coils from another member and trying to test them, using a cheap harbor freight meter, set to 200 ohm primary sides test between 4-5 ohms, move the scale up to 20k and get no reading, step up to 200k and readings are 6800-7000 and other coil is 8600+/-, are these readings (16800)-(18600)? both coils are the same orange/white and white Nippondenso 029700, one coil had a ngk cap and plug side doesn't screw out like stock, the other coil was missing a resistor on one wire, the other looked new ( spring, resistor and contact screw). The meter when turned on to the ohm scale always shows a 1 on the left side of the screen, the 1 goes away when probes are inserted in the plug wires. Am I doing this test wrong?