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how to check my coils

16K views 20 replies 8 participants last post by  tmyrm 
#1 ·
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Hi guys I'm new here. I bought myself a 1978 gl1000. I found out its only running on cylinders 3+4 and after much investigation determined there was no spark at the cylinders. Not a fuel problem. Anyway I took the coils out and just wondering what kind of checks I can do with a meter if any please help Attila.:(
 
#2 ·
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Attila wrote:
Hi guys I'm new here. I bought myself a 1978 gl1000. I found out its only running on cylinders 3+4 and after much investigation determined there was no spark at the cylinders. Not a fuel problem. Anyway I took the coils out and just wondering what kind of checks I can do with a meter if any please help Attila.:(
Attila, I don't have the 1000 coil specs handy but the primary should be somewheres in the 1-3 ohm range & the secondary probably in the 11,000-20,000 ohm range. A good base line is the known good coil you have.

Measure the primary between the power & ground terminals on the coil's case & measure secondary between the two coil plugwire towers.

MAKE SURE you are getting (good) power to that coil & make sure when testing for spark that other plug wire on that coil is either grounded or attached to a spark plug that has it's base grounded. One side of that coil's secondary is the ground leg for the other spark plug so if BOTH wires are off the plugs you won't get a spark on either,.

Twisty
 
#3 ·
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Sounds like yourright coil. But first check your points, condenser, and the wiring going to your coil.

You should have 7 or so volts going to the coils with the ignition on (look for the black and white wire). The reason it's 7 is that the ballast resistor drops it from 12volts.

Take the wires off of the1 and2 spark plugs and measure resistance without the plug caps (the plug caps might have additional resistors built-in). There should beabout 14,000 ohms between the spark plug wires. If the resistance is higher thansay 18,000 ohms your coil is bad. This is your secondary resistance. If your '78 doesn't have the resistors built into the plug caps (check resistance through the plug caps)it might beincorporated into the wires andyou'll have to add 5,000 ohms for each wire or an additional 10,000 ohms.

If the plug caps measure more than about 5,000 ohms apiece your plug caps are bad.

The top of the coils have two wires. One is black/white and the othershould beblue/yellow or yellow (according to the '76 Honda manual). The resistance should be between 2 and 3 ohms between the two wires.
 
#4 ·
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axelwik wrote:
You should have 7 or so volts going to the coils with the ignition on (look for the black and white wire). The reason it's 7 is that the ballast resistor drops it from 12volts.
Axelwik, that is only true IF the points are closed.. If the points are open it will show battery supply voltage minus the voltage drop caused by the impedance of the voltmeter used (not verymuch drop).. A resistor only resists if it has a load on it..

Twisty
 
#5 ·
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twisty wrote:
axelwik wrote:
You should have 7 or so volts going to the coils with the ignition on (look for the black and white wire). The reason it's 7 is that the ballast resistor drops it from 12volts.
Axelwik, that is only true IF the points are closed.. If the points are open it will show battery supply voltage minus the voltage drop caused by the impedance of the voltmeter used (not verymuch drop).. A resistor only resists if it has a load on it..

Twisty
Yep, I guess you're right... learn something every day. To prove your theory I went to the garage an put a resistor across a battery.
 
#9 ·
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Today I finally had some time to investigate the coil problem. Turns out its not the coils. However I have tried to think of other things in the system but just can't get it. Basicly at the points i'm mesuring volts across he points one is 7volts the other 0 this is the cylinders 1+2 side still no spark tried swaping condenser leads still nothing can you guys give me some ideas please. :(

Lost in Canada Attila:?

Btw I replaced the coils no JOY!
 
#12 ·
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Attila wrote:
Today I finally had some time to investigate the coil problem. Turns out its not the coils. However I have tried to think of other things in the system but just can't get it. Basicly at the points i'm mesuring volts across he points one is 7volts the other 0 this is the cylinders 1+2 side still no spark tried swaping condenser leads still nothing can you guys give me some ideas please. :(
Attila, you should have basically battery voltage on open points (minus system resistance & voltmeter impedance load). You should have pretty darn close to "0" volts on the points withthe points closed.

If you don't have a goodvoltage (probably over 10 volts) at the points with the points open (or paper between the points contacts) check your battery's voltage first, then look for poor connectors or grounding wires in the ignition primary supply side like ign switch, connectors, chafed wires, etc.

If you always have voltage even with the points closed then you haveoxidised point contacts (clean or replace them), or a poor points base ground likea poorly grounded distributor base plate.

Place a test light on the pig tail stud on the points & ground the other end of the test light, then crank the engine--IF the light flashes on & off as the engine iscranked your points & primary are working correctly & your problem lies elsewhere.

Twisty
 
#13 ·
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:waving::waving:Welcome to the Best Goldwing Site on the Internet, Atilla!:waving::waving:

Hey, how're those Huns coming along this season? Sorry I couldn't help it! Anyway welcome and keep posting!
 
#14 ·
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Thanks guys great to be a part of this:cheeky1:...Anyways could the problem be a condenser?..Also when I was playing I found a large green wire (probably ground) just hanging there not connected to anything. I connected it to the coil bolt retainer but I think its aluminum, maybe I should place it else were. Also the wires are good from the points to the top connector (the connection block thing) I still need to ring the wires from that point to the coils. . Just wondering has anyone had any trouble with the connector block or bus located at the left side under the fake tank cover. What I could use would be some good pics or a good wiring diagram. I have a manual I bought the one with the green cover. It kind of stinks:baffled:, but hey it was writen a few years ago. Thanks guys.

Attila.:D
 
#15 ·
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Attila wrote:
Thanks guys great to be a part of this:cheeky1:...Anyways could the problem be a condenser?..Also when I was playing I found a large green wire (probably ground) just hanging there not connected to anything. I connected it to the coil bolt retainer but I think its aluminum, maybe I should place it else were. Also the wires are good from the points to the top connector (the connection block thing) I still need to ring the wires from that point to the coils. . Just wondering has anyone had any trouble with the connector block or bus located at the left side under the fake tank cover. What I could use would be some good pics or a good wiring diagram. I have a manual I bought the one with the green cover. It kind of stinks:baffled:, but hey it was writen a few years ago. Thanks guys.

Attila.:D
Yep, it's pretty important to have a well-grounded condenser on this bike. Run a wire froma condenser mounting bolt to the negative terminal of the battery.
 
#16 ·
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Attila wrote:
Thanks guys great to be a part of this:cheeky1:...Anyways could the problem be a condenser?..Also when I was playing I found a large green wire (probably ground) just hanging there not connected to anything. I connected it to the coil bolt retainer but I think its aluminum, maybe I should place it else were. Also the wires are good from the points to the top connector (the connection block thing) I still need to ring the wires from that point to the coils. . Just wondering has anyone had any trouble with the connector block or bus located at the left side under the fake tank cover. What I could use would be some good pics or a good wiring diagram. I have a manual I bought the one with the green cover. It kind of stinks:baffled:, but hey it was writen a few years ago. Thanks guys.

Attila.:D

Attila, you could possibly have a condenser failure but you said -
tried swaping condenser leads still nothing
SO, unless you failed both condensers (highly unlikely) you probably have other problems.

On that green wire? You really need to identify what circuit it belongs to & where it goes to. There are some green wires in the ign circuit. If it was a power wire or primary wire you might have blown a fuse by grounding it.

Start at the coils & MAKE SURE you have GOOD power to both with the ign switch turned on (if not find that problem). Then place a test light on each coils primary low side (that's the wire going to the points from each coil), then crank the engine & see if the test light flashes off & on as the engine is cranked (if not you have aproblem there).

If you have good power TO the coils & the points are grounding the coil pigtails when they close you have other problems- like bad plug wires, fouled spark plugs, open in the resistor caps, failed coil,???

Twisty
 
#17 ·
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:baffled:Well things just keep getting worse. first I found out that on the yellow wire leading to the coil does not carry 12 volts so I started looking for a break in the wires.I disconnect the blinker and puff I lost total power to the bike Best thing is I did not blow any fuses.I orginaly thought it might be an ignition switch but its not I think I fried a ground some were but canot find it this is a nightmare need sleep try again tommorow.:stumped:

Attila:doh:
 
#18 ·
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Ok so far I removed the wire harness and clened it up and inspected all the wires. Then I replaced everything. The good news is I have better and brighter power alround on the bike now. It starts too;). BUT I still lack power at the left hand side points. I'm trying to narrow it down. I swap condenser leads same diff. I try to bridge a ground in several diffrent places no diff. Ive checked the coils and they pass spec. My questions is were is the root of the voltage coming from to the points

still t/s need help please to figure this mess out. Question can brige power from somewhere else to power the coil basicly I have no power at the coil. May be I bought a bum coil it is from the wreckers. thanks..:?
 
#19 ·
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:):)good news I fixed my problem and I am very happy.The problem was the condenser unit:shock:It appers it was damaged in a way that it only allowed cylinders 1+2 to operate in any configuration and thats what made it so confusing. Just have to put it together and I;m ridin baby:1000red:Thanx for everyones help ..

Attila..:cool:
 
#20 ·
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Hey I am new here but I just wanted to say I am glad you got your wing running! I am still fighting the same problem, no fire at 3+4. I have replaced the coils, points and condensers on my 77 wing. The one thing I just found is that I am only getting 3.58 volts at the points to the cylinders that are firing and 1.28 to the points for 3+4 which are not firing. I have checked continuity of the wires and they appear to be ok. So now I am sitting on a milk crate stareing at the bike thinking what next?

Steve
 
#21 ·
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Hey Steve,

I've got exactly the same problem so if there's any chance that you happened to find a solution for this- I'd love to know what it was.
I've replaced the same things you have and got very similar volta readings. What did you find?

Thomas
 
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