Topic: Setting points - extremely weird problem

[goodtryer]

run/stop switch is set to run?
have you tried any starter fluid/spray?
visually confirmed that the choke is closing? (i once had a cable come loose on reassembly)

[Deltarider]

Coils rarely fail and failure of both of them is very unlikely. It is not that difficult to check a few things.
I limit myself to the ignition first.
Verify kill switch is in RUN position.
Make sure neither plugcaps nor HT wires accidently ground to head. CB500s and 550s are notorious for this! It will lead to arcing which is best detected in the dark. If you listen well, you may even hear it crack.
No arcing? Ok, proceed.
Pull plugcaps from sparkplugs and leave the latter where they are.
BTW, if you suspect your coils, now is a good occasion to check resistance of the HT circuit. The coils secundary is around 14-15kΩ, so in total a circuit (either 1+4 or 2+3) will read 24-30kΩ if you have resistor plugcaps. If you read more than say 31kΩ, unscrew plugcaps from the leads to be checked individually. Ideally resistor plugcaps will read around 5kΩ. When over 8kΩ, replace.  BTW, do not run resistor caps and resistor plugs. When you have the choice, I'd prefer resistor caps. Realise that like sparkplugs, plugcaps have a limited lifespan, so when in doubt, replace.
OK, let's proceed. Connect the plugcaps to some reserve sparkplugs and make sure they contact the head well. Crank engine and see if they spark. If they do, you can pull your sparkplugs for inspection, because they will need cleaning or have to be replaced.
If these reserve plugs don't spark, check voltage over each breakerpoint in open position. You should see ca 10 - 12 V.
If there's no current, check coils+ for voltage. You should see 10,5 - 12 V.
Please report findings.

[jakec]

run/stop switch is set to run?
yes

have you tried any starter fluid/spray?
yes. interestingly, I was able to get a few seconds of running on starter fluid before messing with the ignition & coils.

visually confirmed that the choke is closing? (i once had a cable come loose on reassembly)
yes. the bike is all apart (no airbox on currently) so we are watching the choke operate.


Make sure neither plugcaps nor HT wires accidently ground to head. CB500s and 550s are notorious for this! It will lead to arcing which is best detected in the dark. If you listen well, you may even hear it crack.
can you be more specific? how does either ground to the head? exposed plug wire from worn sheathing?

do not run resistor caps and resistor plugs. When you have the choice, I'd prefer resistor caps. Realise that like sparkplugs, plugcaps have a limited lifespan, so when in doubt, replace.
the whole system is original including caps. spark plugs are new.

OK, let's proceed. Connect the plugcaps to some reserve sparkplugs and make sure they contact the head well. Crank engine and see if they spark. If they do, you can pull your sparkplugs for inspection, because they will need cleaning or have to be replaced.
will do. the plugs in the engine now are new however. so you think there's a possibility one is defective? I know at least 2 of them are sparking as those are the two I used to do the timing.

New coils were already going to be ordered as we are getting the type where you can install your own longer wires for custom mounting application.

[dave500]

try advancing the whole timing plate a little,static setting often results in retarded timing,once its running use a strobe to the full advance method and forget the f mark.

[cat]

so heres where we're at with this peculiar bike:

after realizing the advancer was assembled backwards, we swapped it, adjusted timing, and found both 1+4 and 2+3 were all sparking. so we tried to kick the engine and see if it would run. she would not.

since the new coils came in (https://4into1.com/magna-5-ohm-coils-and-caps-honda-cb350f-400f-500k-550/) we went ahead and installed these.
to remove some variables, we wired the coils directly to the battery. wired the points plate to the coils using yellow/blue wires, then spliced a wire connected to each of the coils black wires, wired them to the battery +. while doing this, we found 1+4 produced spark, but 2+3 did not. we verified the cabling and assembly of the coils, all looked to be correct. still no spark for 2+3.

since the original coils had shown spark on all plugs, we retraced our steps and reinstalled the old coils. again, we removed some variables and wired the coils directly to the battery. again, 1+4 shows spark, 2+3 did not.

this is a very weird problem since before switching out the old coils for the new coils, we had spark on all 4 plugs.

going back today, we will wire it up as they were previously, instead of bypassing the wiring harness and connecting directly to the battery, and check the spark.

does anyone have any insight into why this might be happening or what to check next? points were good, spark was good, engine didnt run, installed new coils, now no spark on 2+3, reinstalled old coils, now still no spark on 2+3

[goodtryer]

Somebody will correct me if I'm wrong I think you can swap the blue & yellow connections as a test to see if the problem moves to the alternate point.

[cat]

That is something we didnt try last night, ill make sure to add that to the list of things to test out tonight.

[jakec]

If you switch the blue and yellow wires and the non spark condition switches than you have ruled out the coils / wires / caps / plugs? and you know it is something to do with the points plate? That is the only part that hasn't been replaced,

ALTHOUGH we JUST did the timing and it was fine, spark on both coils. Rebuilt advancer (correctly), checked both condensers which tested OK, cleaned point contacts, ruled out wiring harness by circumventing...

The problem with the spark seems to come and go and every time we change a variable the outcome also changes.

[Spanner 1]

My money's on #$%*ty main frame/motor ground. Maybe loose or corroded or trying to ground thru' painted frame motor mount.

[seanbarney41]

I had a weird problem like this one time.  It was because I had assembled the coil brackets wrong.  There are some tiny metal loops that stick out of the ends of the coils and they were contacting the coil brackets because I had something flipped around wrong.  Make sure your coils are correctly isolated from the brackets.  The brackets should only touch the brackets at their proper mounting location.  I only caught this by sourcing some unmolested coils and brackets to compare with what I had done.

[HondaMan]

The advance is assembled correctly and the pin in the correct position. The battery is brand new and charged. The headlight hi / lo switch is a little finicky so the headlamp I actually able to be turned off. The plugs are correct NGKs and the caps are stock. We trimmed the leads and firmly seated the caps. I also cleaned the points with light sand paper. I have not tested the condensers.

Got $1 on condensors. Theres a reason why they are so cheap

I'll see that $1 and raise you $5.
It's probably the Daiichi condensors....I have now experienced 100% failure of them on 11 engines in the past 5 years, right out of their box.

[754]

Also if not careful mounting point sets  you could be grounding  them... pretty easy to do.

[Deltarider]

Reread reply #20.

[cat]

So we got the bike running tonight.

Not sure exactly what the problem was but I suspect the condensers where grounding to the plate at some point. I rearranged the order of the condenser wires and points wires on the bolts connecting to the attachment tab on the plate, tested afterwards and was getting spark on all 4 plugs.

The spark was a little weird, each kick there was a little burst of sparks all at once. Not sure if that is a problem or not.

Engine would only start with the choke all the way on. It would die immediately if the choke was turned off or if we open the throttle. It was also backfiring a lot.

We think this means its getting too much air, so I'm going to try to mess with the air screws. Currently I have them at 1.5 turns. Maybe look for air leaks. Are there other factors where too much air is entering the system elsewhere?

[dave500]

dont confuse ignition with an air fuel problem,get that ignition squared away 100% first or you WILL forever chase your tail!i just use electronic on these,its far easier and more precise especially as these have two point sets,most people have trouble with one points set let alone sync two sets?

[bryanj]

If all 4 plugs spark together you still have a problem

[Ryan66]

dont confuse ignition with an air fuel problem,get that ignition squared away 100% first or you WILL forever chase your tail!i just use electronic on these,its far easier and more precise especially as these have two point sets,most people have trouble with one points set let alone sync two sets?

If its a 550 isnt there a weird draw on the coils even with 5 ohm if you go to the electronic ignitions?

[bryanj]

Not a wierd draw but a more constant one that drains the battery at lower revs

[Ryan66]

Not a wierd draw but a more constant one that drains the battery at lower revs

Whats the solution to that?

[Don R]

 These just have a low output charging system, if they lug around town a lot the battery will not charge up and may slowly drain. Electronic ign. just adds to the load. Some guys have no problem, some guys swap the bulbs for led's, Your mileage may vary.

[Ryan66]

These just have a low output charging system, if they lug around town a lot the battery will not charge up and may slowly drain. Electronic ign. just adds to the load. Some guys have no problem, some guys swap the bulbs for led's, Your mileage may vary.

Do the different ohm coils make a difference?

[jakec]

If all 4 plugs spark together you still have a problem

Kicking the engine over you could see what seemed like a burst of sparks from the plug. You think the coils are all firing together? It seems like we had previously solved that problem when I set the timing.

[jakec]

I have a dynatek ignition on my 400. SHould we just take it off and install it on the 550? Not sure if their advancer / cams are compatible? That would be one way to try and rule out the points, wouldn't it?

[goodtryer]

Nope. That just adds another component to the mix and more connections.

"Kicking the engine over you could see what seemed like a burst of sparks from the plug."

Does it look the same on all plugs, do they all spark multiple times per kick?

Any way you could show a video?

[jakec]

We tested the #3 & #4 plugs separately, never at the same time. With each kick you would be maybe 3-4 sparks, instead of the 1-2 I would expect.