No spark ... electrical gremlins. 1972 CL350 K4

[alexmac]

At the end of last summer, I installed new Dyna coils, a Bore-Tech electronic ignition and a Rick's Motorsport Electrics charging coil.
I followed the instructions for each component and wired everything back up the way it looked when I started... with the new components
installed. The days were getting cold. So I put everything back together ready for a restart in the spring. Like a dummy, I didn't think
to test it.

I tried to start it earlier this week and it wouldn't turn over because I thought the battery was dead. I tried all the buttons and even when I hit
the horn the headlight would dim.

So I went and bought a new battery and tried to start it. The starter motor runs but no start. Oddly though, the horn doesn't work either even
though when I had the toasted battery in it... the headlight would dim.

All signals, lights, brakes everything works. I then pulled out the spark plug and hit the starter and looked for spark... nothing.

I am not exactly sure where to start looking for where the problem is... can you give me some advice of where to start. I don't have a meter so I need to go
buy one.

It would be ideal if there were some kind of flowchart for this kind of thing.

 

[cgguy09]

Hey man,
I really don't have any advice other than check all your connections & by check I mean pull them apart and put them back in...you'd be surprised how often that'll shake the gremlins out. The symptoms sound something akin to a grounded wire.

Electrical questions (like yours) rarely have answers like carb or engine questions because electric stuff is so idiosyncratic. So, there are few prevailing "standard" answers...if any answers at all.

I wrote a post up here with the same sort of problems & I pretty much was the only one who wrote on the post(answering my own questions)...until I was done & someone said "Good job"

I'm sure that doesn't help, but good luck anyway brother.

 

[alexmac]

...wow... that sounds very time consuming given the number of connections.

 

[lingo]

Start with the ones that you disturbed when you did all of the changes. If it worked before you screwed with it and now it doesn't, it must have been something that you did.

 

[TheCoffeeGuy]

Lets do the easy stuff first. The horn sounds like its seized. There is a small screw on one side of the horn, screwing it in separates the diaphragm and inwards makes them slide together. Usually moving it in and out loosens things up.

Re set the static timing by the instructions in the Dyna kit. Then set them again.

Check the plug caps and make sure your wires have contact with the screw inside the end of the cap. This sometimes means shortening the plug wire by 1/2 inch to get good wire on the screw again.

As well check the integrity of the lead wires going to the Dyna, they often dry up and crack off.

 

[alexmac]

Ok. I tried to check to see if there is power coming from the coil today.

I popped off the spark plug wire at the connection at the coil and placed the positive lead inside where
the wire connects and grounded the negative lead then hit the starter. Nothing.

I am using this meter. Fluke 7-600
http://www.fluke.com/fluke/usen/electrical-testers/Electrical-Testers/Fluke-7-600.htm?PID=56125

The coils are Dyna DC10-1 5ohm coils



On each of the coils there are 2 screws. 1 black wire to each and a yellow and blue wire ... yellow to one blue to the other.

I took the meter and I grounded the negative lead and i put the positive lead on each of the screws and hit the starter button.
Each time... the meter registered a jump.

Could it be that I have the coils cross-wired or something?

 

[Bert Jan]

ehh.. you're using the meter to check for spark? The black wires need power on them to load the coils. The yellow and blue go to points. Those points tell the coils when to release the current.

No need for meter here, coils were new right? Power em up and they'll go.

you're also mismatching the words 'wire' and 'screw' am i right?

 

[alexmac]

I took the meter and I grounded the negative lead and i put the positive lead on each of screws (which connect the wires to the coil) and hit the starter button.
Each time... the meter registered a jump from 5ohms to -12 ohms .... but show no power.

I installed a Bore-Tech Electronic BT-05EL on my 1972 last summer. The installation went pretty good I thought
and I set the static timing at time of installation...no problems.
I didn't have a chance to try to start the bike until this spring and when I did. It looks like there isn't any power getting to the coils.(which are brand new).

I put a multimeter on the red lead from the ignition... (which connect to the black wires on the coil) which should send the power to the coils and there is nothing. All that the meter shows is that lead shows -12 ohms when you hit the starter button.

 

[lingo]

Is it reading ohms or volts?

 

[alexmac]

It is a meter that automatically switches between Ohms and volts depending on what is going through the circuit. If there is no power is just beeps and shows the resistance between the two leads. If there is power... it doesn't make any noise and shows the voltage.

I tested it on the 2 terminals of the battery ... shows volts.

Anywhere else I tried it ... shows only ohms. No power.

 

[xxthegonzxx]

I'm having similar issues. Just purchased Dynatek coils (3 ohm) and have them installed on my '78 cb750f. I get spark on both coils, but ONLY if they yellow wire is attached. The blue one does nothing. I think you should check your wires.

 

[Bert Jan]

Ok, flowchart galore;

Install new battery.
Check for power on black wire with key in 'on' position
Check for power at the black wire going to the coils
Check yellow and blue wire for current flow (on/off) whilst engine is kicked. To do so, put one end of the multimeter on the yellow(or blue) wire at the coil, and the other end at the points (or electrionic ignition)

If all above are ok, your bike should run, taken you have set timing correct, valves are set ok and ignition is ok. I've got no experience with the Bore-Tech, but it should give a spark anyway. If it gives no spark at all and the black wire going to the coils is hot, the problem is in the bore-tech. The yellow and blue wire tell the coils when to release power. When black wire is hot, the coils load. If the blue and yellow wire do not open or close, the circuit is not completed and there will be no spark. You could put the yellow (or blue) wire to ground directly (detach bore-tech) and check for spark. Basicly, the ignition makes a connection at the right time between the coils and the ground. Thats the point the spark occurs.