Ignition coil questions

[crozell]

1979, been chasing some bogging issues and want to rule out the ignition system. Pick-up coils check out. Removed both ignition coils, primary coils are within spec but on both secondary coils i get nothing. The big starts and runs so this doesn't make sense... I have removed the spark plug boots and am sticking the probes straight into the wire...Am i missing something?

[DiverRay]

wire to wire on the coil should be close to zero ohms. The plug caps have 5K ohm resistors built in. Check the plug caps and verify that they are not above 5K ohm.
If you do buy new coils, you can get 5 ohm coils and bypass the ballast resistor.

[crozell]

Thanks Ray, I’m just confused bc according to the manual I should be getting 15 ohms wire to wire- unless I’m reading it wrong?

[Larrym]

want to rule out the ignition system

BTDT when I installed cheepee carb kits from Ebay that made my bike run like garbage. (o-_-o)

I mean...fOaR troubleshooting/isolation purposes it's kinda a "MUST DO", right? (O_o)

I did the same resistance checks (primary/secondary) with and without the plug caps. Even did the caps seperately. (*´-｀*)

Showed as GOOD and yet the bike continued to bog, stumble, pop, lag, and otherwise disappoint in the 1 to 4 K Rpms. ¯\_(⊙_ʖ⊙)_/¯

So...to TOTALLY rule out the coils as the source of the trouble in a way I, myself could see/trust? ¯\_(⊙_ʖ⊙)_/¯

I used a 10 Amp 12 Volt DPDT relay set up to turn itself off/on (Chatter/Buzz) and connected it to the ballast resistor/coils via a gel cell. ʅ(°ヮ°)ʃ

Plugs were removed, alligator clips attached from the plug cathodes to the engine fins, and inserteded in the caps. (´～｀ヾ)

Could only do 1/4 or 2/3 at a time but when I flipped the switch they sparkies started and continued fOaR 2 minutes w/o missing a beat. ᕕ(︶‿︶)ᕗ

ACTIVE PERFORMANCE TEST COMPLETED to my own satisfaction. ┗( ＾0＾)┓

You do know that iffin' you're not satisfied/trusting with the results of doing the resistance checks on the P/U coils? (・´ｪ｀・)

You can rotate the crankshaft to the place where the reluctor is in the right position (depending on which P/U coil you wanna test...) and then "Fliggle" (Flip/Wiggle) the vac advance connecting rod with the key on. (o-_-o)

THAT makes sparkies you can see iffin you gots yur plugs out and alligator clipped to the engine. (o-_-o)

Yet another "function" test a bit mOaR convincing than the usual passive resitance checks shown in the repair manual. (⌒_⌒)

[Larrym]

Note- In my box of XS1100 Electrical Parts I've got a pair of used ignition coils and plug caps. ( •_•)

O'course I did the usual resisistance checks on THEM with the readings showing they're good too. (･‿･)

BUT... even on these spares I did an active function test. (•﹏•)

Didn't use the DPDT relay set up to chatter, tho. (╯•﹏•╰)

I just grabbed a 12 Volt car battery, color coded alligator clips wit wires attached, a spare ballast resistor, the coils, and 2 (two screwdrivers). (＾-＾)

Hooked everything up with spark plugs inserted and used the screwdriver(s) as a "switch". (☉_☉)

Y'know... put the screwdriver shafts together like yur making a cross to fend off a vampire? (㇏(•̀ᵥᵥ•́)ノ)

Then slide either one offa the other to break the electrical connection and the coils made the sparks at the plugs. (∩｀-´)⊃

Totally as low budget as you can go but it DID show the coils wurky so they're stayin' in the box til I need'em. (ღ˘‿˘ற)

[Radioguylogs]

I once tried testing ignition coils on a bench using a 10A 12V power supply. I just did a manual make/break on the primary.

I didn't get the plugs to spark, yet it turned out the coils were good.

I had wondered if the condenser was needed.

I wonder why this test works for Larry and not for me?

[Larrym]

I once tried testing ignition coils on a bench using a 10A 12V power supply. I just did a manual make/break on the primary.

I didn't get the plugs to spark, yet it turned out the coils were good.

I had wondered if the condenser was needed.

I wonder why this test works for Larry and not for me?

Right! (－‸ ლ)

Left out an impor'unt detail. (•﹏•)

I ALWAYS have the spark plugs "grounded" to the fins/engine with these-



That's fOaR a secure/easy path from the anode (round thingy) to the cathode (thingy you bend to get the gap right) and THEN to dissipate into the "ground" on the engine. (^_^)

Disclaimer- might have the anode/cathode thingy backwurdz so don't be hatin'.......

W/O that easy path fOaR the high voltage electons? (O_o)

Like...as if you just laid the spark plugs on the engine somewheres and hoped/wished that'd be good enuf and it wasn't? (；☉_☉)

The field would build up and collapse like nurmal with the make/break BUT the high voltage electrons wouldn't have a easy-peasy path to follow and discharge into. (ﹷ _ ﹷ)

The anode (round thingy on the spark plug) just gets all charged up and stays that-a-way READY to discharge but CAN"T. (≖ ︿ ≖ )

Insert "blue-balls" analogy here....(/‿＼)

Mebbe bleed off a little charge thru the air molecules as they pass by.... （ ͡◕ ᴗ◕)つ━━✫・*。

Oor even wurse! Those high voltage electons wanna jump so BADLY that they'll even try to find/exploit ANY weaknesses in the insulation of the coil body or high tension leads. And iffin' they do find a weakness they'll choose THAT path insteada the one we want/need. =͟͟͞͞ =͟͟͞͞ ﾍ ( ´ Д `)ﾉ

Translation? Totally possible to "Blow-out" the coils so they're arcing/sparking INTERNALLY insteada devilering the spark where we want it. (っ˘̩╭╮˘̩)っ

SO... even when I did the low budget/alligator clips/ballast resistor/screwdrivers as a switch test? (O_o)

I had the spark plugs connected/clipped to a piece of electrical counduit which was a solid earth ground. (´～｀ヾ)

GOTTA have a place fOaR them High volatage electons to jump to and dissipate so's the next time they can build up and do it again. (*´_ゝ｀)

[Larrym]

been chasing some bogging issues

Now back to the OP/Crozell reason FOAR getting our input in the foist place. (^_^)

Provided the coils are good per the repair manual resistance checks and the optional "Active Performance Test" like they were in my situation? (O_o)

My next step was to verify the operation of the vacuum advance per the repair manual. (๑˘ᵕ˘)

(Which passed with flying colors btw...)

After that I hooked up an inductive timing light to #1 spark plug wire to verify ignition timing per the repair manual. (੭ºัᴗºั)

(again... spot on where it should be...)

While I had the timing light connected I verified that the MECHANICAL Advance actually advanced the timing when I brought the rpms up and did the opposite when I lowered the rpms like it's s'posed to. (੭ˊᵕˋ)੭*

(Yup....mechanical advance wurky too...)

In my case, like I stated befOaR, in the end the REAL problem was the cheepee Ebay carb kits I had bought/installed. ( •_•)>⌐■-■

Regardless, my bike wuz running like KrAp and so I too had to make a whole list of things to test/inspect just to get the EVIDENCE I needed to circle back round to the kits. (⊙▂⊙)

I know... a jagged little pill to swallow about doing all these tests and not finding the smoking gun fOaR why the bike is bogging. (_Oo)

That is until/unless you DO find something, right? (⊙‿⊙)

[crozell]

checked the resistance on the plug caps...two were over 8, other two were slightly under 5...could be a clue...still stumped on why manual says 15 on the secondary and i am getting nothing.... would the high resistance on the two plug caps lead to bogging in the 1k-3k range?

[Larrym]

stumped on why manual says 15 on the secondary and i am getting nothing

"I am getting nothing" has ME confusled. (O_o)

Do you mean that you are getting ZERO Ohms which would mean total continuity without ANY resistance? (ー_ーゞ

(That would mean the coils are Shorted out and wouldn't work at all...)

Oor...do you mean you're meter isn't registering anything as the resistance is infinite? (¯―¯ ٥)
(That would mean the coils are an open circuit and wouldn't work at all...)

The simple fact that the engine starts/runs would seem to indicate the coils are working electrically. (O_O)

If you can, I'd suggest getting an inductive timing light and hooking it up to EACH high tension/spark plug wire in turn.

Iffin' the coil/wire/plug wurky and makes a spark? (O_o)

Then the timing light will flash. (Doesn't matter where it is unless you're actually verifying #1 cylinder timing...)

Just look for consistent flashes on each cylinder/spark plug wire and ACCEPT your coils as good iffin' they do flash. (O_O)

Clearly..the whole "resistance checks" process is providing misleading/confusing data if I'm understanding you properly. (O_o)

I'm going to ask in plain and simple language...

Have you or the previous owner(s) ever bought/installed aftermarket carb kits from Ebay? ( 　ﾟ ,_ゝﾟ)

The "bogging" you refer to is symptom related to those kits. (◔ヘ◔)

IMHO, It is also common fOaR owners to start looking at other causes (ignition coils, etc..) and start replacing those parts even tho, in the end, they are NOT at fault or faulty. (◔_◔)

would the high resistance on the two plug caps lead to bogging in the 1k-3k range?

My honest opinion? (O_o)

NO. It didn't on my bike and therfore not likely on yours. (⊙_☉)

The cause of the bogging on MY bike was due to the faulty jets and faulty needles/seats fOaR the fuel floats in the carbureators. (◡︵◡)

[DiverRay]

Over 8K is too high a resistance for the plug caps. I replaced all four of mine with non-resistor caps and use resistor spark plugs, Iridium NGK. It's been a while, so I don't have the part number handy, but they did fit Honda automobiles, so were easy to find.

[DEEBS11]

Here is one of the best kept electronic secrets in my arsenal. This is an old fashioned two-way radio oscillator or multi vibrator. 2 pins are positive and negative. 2 pins are in and out contacts. They work just like points. You could also use this to make quite the cattle prod also.

Positive to your coil and negative through the oscillator and to the negative of the coil. Don't electrocute yourself with this. It's quite easy.

[DEEBS11]

https://www.youtube.com/watch?v=S1tD1-JTb1w

[DEEBS11]

https://www.youtube.com/watch?v=1EabqJJnWhc

[crozell]

UPDATE- messed around with the coils, cut them back to expose wire. One was getting 16.5 and the other absolutely nothing. I am confident that one coil is bad. Perhaps the "bogging" is actually two cylinders not firing and after 3k they somehow get spark? I have a donor bike that I will swap the coils out from. Either way, I will need to replace that coil. Best to swap out both? Any recommendations/advice on sourcing them?