Topic: (no) Spark on 1, no spark on 4?

[buffaloejon]

Problem is exactly as described. I've got the thing taken apart, to adjust valves and cam chain tensioner, and I notice sparkplug lead 4 and 2 are both labeled 2 in sharpie. So, I'm double checking timing and spark, just to make d*** sure, cause apparently the PO is a tard. Anywho, 1 sparks fine, 2 sparks fine, 3 sparks GREAT, making me think I have a weak spark on the other 2? I can't say, because I"m not sure what it should look/sound like. Get to 4, and voila, no spark. At either F mark. Turn it over with the starter, still no spark anywhere. Nothing to see, no sound. Definitely no spark.

Aftermarket coils/ dyna s ignition, both installed by PO on 750 K6. I'm guessing that one of the coils is bad? How hard are these to find and how much?

I REALLY wanted to get her riding today

[ekpent]

Well one coil makes spark for 1 and 4 and the other coil makes the spark for 2 and 3. If you have spark on #1 then 4 would probably be getting power also. Check the wire and cap to be sure its on good and making good contact  and make sure that the spark plug is good for starters.Those wires are removable if its an aftermarket coil correct ? What color are they?

[buffaloejon]

The plug is good, I checked all 4 with the same plug for consistencies' sake. I looked up these coils and they're like 200 new, so I can't imagine they've gone bad in only a couple years? Checking the cap now. Gonna switch up the leads and see if that changes anything.

[ekpent]

Coils are pretty tough,don't see them going bad to often,and the fact you have spark on #1 means its working,at least on that outlet.

[buffaloejon]

Changed the lead to the other coil, sparks fine. Changed the lead to the other outlet on the original coil, no neither 1 nor 4 sparks. Could it simply be low voltage from the battery, which is why I thought it was running ok before?

I'm gonna adjust valves and cam chain tensioner, and then see if they'll spark with the other 3 cylinders actually firing.

[TwoTired]

The coils fire spark plugs in pairs.  You can't check them individually without its partner hooked up, too.  Current flows in a loop, out to one plug through the cylinder head to the other plug and back on its spark lead back to the coil.

If you are checking them individually and the partner unconnected, then you are at the mercy of a stray arc completing the circuit.  Might get one, might not.

[buffaloejon]

Update, its running on 2 cylinders.

Is there any way to test to see if the coil is still good? That's a good chunk o change...

[KingCustomCycles.com]

"aftermarlet coils"  that leaves you guessing as far as coil testing.  The Honda manual might be a start.  Also, you can put OEM coils back on the bike and use that Dyna ignition with them.  That would be about $30.00 last time I checked for both coils off eBay.  An alternative would be early Goldwing coils, also cheap and readily available. 

[buffaloejon]

The aftermarket coils are Accel 140403's, 3 ohm resistance.
Gonna test the coils after dinner to see what I've got.

[crazypj]

As first reply said, if 1 sparks, 4 has to, unless voltage is tracking where leads attach?
 It's a lead or plug problem, you have a circuit or #1 wouldn't spark

[buffaloejon]

Right. I'm not sure that 1 was ever sparking to tell you the truth.

[buffaloejon]

Alright well, the resistance readings on the two plugs that don't go to the spark plugs (correct me if those are the wrong places to take readings) reads right on about 3 ohms. 3.2 or so on both coils. So I'm guessing faulty wiring between the coils and the battery somewhere? Are there any differences in how the stock points are wired and the dyna s? I need to check how these are wired, but I only have a wiring diagram for stock. Also, does it matter which way the two wires going to each coil is attached to the individual coil? Meaning, could they be switched without any problem.

[buffaloejon]

Ok.
Switched the four wires on the actual coils, and 1-4 still has no spark, so its the wiring of the blue wire thats bad, or a faulty dyna s power module.

[crazypj]

Swapping blue and yellow wires at coil will eliminate coil problem (if it works 2nd coil)
 Not sure of Dyna testing, either they work or they don't