Topic: dyna s ignition test. problems now points problems too yay!

[750four]

Looking for a good way to check my ignition system. It a cb750 with dyna 3 ohm coils and dyna s ignitin. I've had it running . Then rewired a few things.

In the process i had crossed the battery terminals by accident. Fried a wire in the process. Kinda worried now cause its hard to start and dies after a few seconds.

I also noticed that cyld2 and 3 run hot while 1 and 4 are dead cold on the headers. Thats afetr running for 20 seconds. I have continuity from the ign to the coils and even put a timing light on the wires to check for fire. They all are firing. 3 and 4 coil bad? To hot?

[burmashave]

Have you checked resistance in the coils themselves? You should have about 3 ohms resistance on the ignition side of the coils, the spark wire side will show lots of resistance. I don't have a figure, but I'm guessing it should be in the 10-15k ohm range.

As for the ignition, tlhis prolly isn't the answer that you want, but you can send it back to Dyna, and they'll test it. I had a prob with my Dyna 2k, and they said they'd check it. If it failed, they would have sold me a replacement at a discount. I didn't feel like waiting, so I got a replacement module from Z1.

[Roach]

same thing just happend to me.. just went to z1 and now i got a new one.. the way to test it is to

go to the dyna web site and get the instructions for the dyna-s it tells you how to test the system with a timing light

[SF]

KOOL LOOKIN RIGID DO YOU HAVE A BUILD THREAD?

[750four]

no build thread really, sorry. I started one when I first bought the bike, but it had to take a backseat  to life a few times. So my work was off and on and really didn't have time to document much. I did build this thing from the ground up though.

Built the hardtail, raked it a bit. built the oil tank, battery box, seat , seat hinge, headlight mount, rebuilt the head and added some goodies here and there. Thanks. maybe I'll get some pics that I did snap here and there together later. But I want to get it finished to ride first.!! haha.

[750four]

"Hummm, that's odd" 

I said that a few times tonight. May have found a few mistakes I've made , I need some opinions:

1. I have my coils mounted to my frame via some ground clamps I found at homedepot. To get the 2 of them to fit onto the 2 clamps I had to make a short steel bracket. So the brackets have 3 holes. the 2 outer holes mount the 1-4 coil and the 2-3 coil. The center goes to the ground clamp attached to the frame. 1 clamp top and 1 clamp bottom. hope that makes sense.

2. Well, thinking it was a handy place for a ground I also attached my battery ground to the clamp. Now remember I had crossed my battery terminals by accident which may have started this mess.

3. While testing my dyna unit tonight I wasn't getting a spark on 1-4. I tried a few times. While preparing to make the swap to see if the coils where the problem I turned the ignition key off. I heard a "tick" like an electrical discharge. So I just swapped the spark plugs from the 3 and the 4 and tried the test the same way. I have spark on 4 and spark on 3 also now??

4. While pulling the dyna coils off I noticed that my coil grounds had become magnetic? and the 1-4 coil was much warmer than the 2-3 huh....

5. I need an explanation on how to check for resistance on these coils. The only reading that I can get is ohms from the power in and the signal wire in. It's at 3.5ish

I'm sorry if this is hard to read, but I'm tired and so confused uhhh.....

[750four]

the best pic I had of the coil mount

[burmashave]

I have a better answer for you. TwoTired wrote up a comprehensive guide for testing coils:

http://forums.sohc4.net/index.php?topic=5752.msg8383#msg8383

[SF]

WHEN YOU GET THE COILS FIGURED OUT, LOAD UP SOME PICS THAT WOULD BE GREAT.

[750four]

could use a  bit of help. ....

[burmashave]

O.K., I'm a bit fuzzy. Which part do you need help with? Is the coil mounts, the coils themselves, or general ignition troubleshooting?

[750four]

I'm trying to determine if the coils are bad. I have a 3.5 ohm reading between the 2 innies. and 1930 cont' testing between the innie and the outtie. But my tester is a cheap digital read out. Both coils are consistant with each other. And I have no cont' between both of the outties.
 Innies = terminals for the switched power and the signal wire
 Outties = terminals for the plug wires

I checked my dyna s plate via instructions that came with it. It 's getting a constant voltage of 11ish and battery is sitting at 12V. Rotated the rotor around several times to see if I could find a reading where the power was switched back off to read 12v but no dice. not looking good

[burmashave]

As for the cheapie multimeter, it's probably just fine for working on an SOHC/4. There's a FAQ about which multimeter to buy, and it boils down to the fact that most basic multimeters will do. Many prefer a digital MM.

If I understand, so far, there's 3.5 ohms on the innie side. That's good.

Is there continuity between any innie with any outie?

So far, so good. I would guess that your multimeter (MM) doesn't show the actual resistance between the outie terminals. The resistance between them should be in the 10,000 to 15,000 ohms range if I recall correctly.

That leaves testing the coils as TwoTired suggests:

If your spark plug boots are still installed, insert a spark plug in each one and arrange them so that the threads of each plug are touching the other. Each time you apply and disconnect 12v to the “gazinta” wires, both spark plugs should display a visible arc between the center electrode and the plug body electrode.

I'd connect a wire from the battery neg terminal to the coil. I'd connect another to the coil terminal and then touch the end to battery pos. If they spark, the coils are good.

[750four]

Ran a few test the other day and determined the dyna s ign is not turning on and off. Coils may be good. I think I may send it back to be checked and repaired.

So I dug up the old points plate and reinstalled it. Set the gap best I could. Kind of a pain to get right. Wired up the coils and put on a new set of plug caps. I'm getting fire on 2 3 but nothing on 1 4. Noth coils seem good. Both are right at 5 ohms.

Could my points or condeser be bad. Points are clean and functioning. Rewired them to the coils. Condesors gone bad? Would it not fire though?

[750four]

points are solved, I had a bad point on the 1-4 side. It's running, but not ridable yet. My carbs are set for 3 ohm coils and that dyna s ignition.

[burmashave]

So the ignition is sorted out?

[750four]

Sent my set up back into Dynatek for an inspection. The guy I talked to was cool. If parts are bad than they'll offer me a brand new replacement for a fraction of the price of new parts. I'm hoping that the coils are both good.

But the points and 5 ohm stock coils aren't a good match for the over carbed setup I have on it. I already needed to go down a size on jets to get the carbs to work correctly. So lossing that hot spark isn't helping at all.