No spark

[alehman]

Hi all,

I've tried all I can for now on this problem so now I defer to your wisdom. I have no spark at any of my plugs. Let me tell you some stuff about my bike.

spark wires are new.
spark plug caps are new.
coils are outwardly intact and passed multimeter test.
Original rectifier failed multimeter testing and was replaced--- thought that would do the trick, but no dice.

some potential problems:

I do not have the bolts for the coils, and as a consequence I cannot (reliably) attach to the frame the green ground wire that is supposed to go underneath the bolt that holds the coils on. Every time I've tried to start the bike, I've had my friend holding the coils/ground wire to the frame. Question: is this THE frame ground? also, do the coils need to be attached to the frame to be grounded or are they grounded on the engine block through the spark plugs?



another problem is that on my starter solenoid, the fuse holder has been removed and replaced with a bright blue wire. Clearly it should be replaced, but will it pose any immediate problems in the near future or now?

Thanks in advance.

[alehman]

I should also mention that my bike is a '79.

[TOOLS1]

A good hosing would do wonders, for the bike. Unless, you plan to plant potatoes on it.
The coils should definitely be grounded, but are, you getting juice to the coils? Also, you should install some blade type fuse holders in place of the wire.
TOOLS

[alehman]

haha yeah it's a little dirty. The connections between the coils and the spark units are good, but I didn't test the connection between the coils and the kill switch or the connection between the kill switch and the rectifier/regulator. How would you test to see if the coils are getting juice?

[alehman]

also, would you or anyone else happen to know the dimensions of the bolts used to attach the coils?

[TOOLS1]

To test, for voltage, just use a test light, or an OHM meter set to DC voltage. Not sure of the bolts length, but they are a 6mm bolt.
TOOLS

[alehman]

Thanks tools. Is the threading on those bolts some standard dimension?

[TOOLS1]

I think it is 1.5.
TOOLS

[Re-run]

Have you checked the pulser?

[sgtslag]

Have you downloaded the FSM from the home page?  Everything you need should be in it; the Clymer manual for these bikes is also quite good, in my opinion -- e-Bay, Amazon.com, etc.  You may want to study the schematic wiring diagram.  This will show the electrical paths, which will show you where to test for voltage, to see if the whole is wired correctly.

This bike uses a CDI ignition system, rather than points and a condenser.  I am not familiar with how to troubleshoot it, but the FSM covers it, as does Clymer.  Some basics on coils:  they are a transformer; the primary side receives 12 Volt pulses from the CDI system, which is stepped up to around 10,000 Volts, on the secondary side; the secondary side is connected to the spark plugs, where the high voltage jumps across the electrode gap, igniting the fuel-air mixture within the cylinders; both the primary, and the secondary sides of the coils need to be grounded, both through the metal frame, and the engine block (they connect to the Negative terminal of the Battery -- circuit ground, not Earth ground).

The troubleshooting procedures should be listed in the FSM.  Follow the steps, and let us know if you get stuck,  It sounds like you have tested the individual parts, but you have not verified power is being delivered to each portion of the ignition system, yet.  That is your next step, to verify that power is being delivered to the CDI system, and from there, to the primary (low voltage) inputs on the coils.  Divide it down, as you progress.  As you verify power delivery (CDI, then the primary windings on the coils -- low voltage side of the circuit, be careful after that!), eventually, you will find a point where power is not reaching, and then you will know which component is failing.

Have you checked all of the fuses?  They're underneath the cover, middle of the handlebars, two Phillips screws.  Be careful, though, as they are live -- if you drop a screwdriver on them, you will likely blow one, or more, of the fuses.

As Tools said, get a modern fuse holder, 30 Amp ACM type, blade fuses, and put some ring connectors on its ends.  Then connect it where the fusible link (30 Amps) is supposed to be, under the left side cover.  This is the main fuse for the whole bike.  If you put a wire in place of the fuse/fusible link, a fire could start, anywhere on the bike, including beneath your seat!  Cheers!

[alehman]

Thanks guys. I got my hands on the right bolts to attach the coils/frame ground to the frame, and now I have a nice bright spark. The bike still doesn't fire, I'll probably start a different thread to talk about the issues there. Really appreciate the help guys.

[alehman]

also, sgtslag, thanks for the tips on the fuses. I should probably take care of that right away. Where do you think I can buy the correct fuse holder?

[sgtslag]

I got mine from Wal-Mart, but any hardware store, or auto parts store, should have them in stock.  Wal-Mart will likely have the best price -- they're located in the automotive wiring section, along with an assortment of fuses for them.  Cheers!