Topic: Still chasing ignition woes

[Bankerdanny]

I know there are multiple threads on this topic and I have read a lot of them, but I still can't seem to solve the 2-3 spark issue I have been having for over a year.

I had this issue briefly at the beginning of my week long trip last year, but I replaced the 2-3 condenser, which had been rubbing on something and had a bare spot in the insulation on the wire out, and that seemed to solve it until literally the last few miles of the trip, when it came back and hasn't gone away.

I have tried on and off to solve it to no avail.

- Yesterday I set the points and double checked the timing.
- When I swap the blue wire from the 1-4 points into the yellow wire into the 2-3 coil I get a nice fat spark, so the problem would seem to be the 2-3 circuit.
- I have measured the plug ends and coil resistance and all are within spec.
- I tried running a new yellow wire from the points to the coil and it made no difference.
- I installed new terminal ends on every wire in the 2-3 points circuit.
- I swapped out the condenser for another I had on hand.
- I reconnected my Hondaman ignition, which isn't dependent on the condensers, and it didn't help.

I am at a loss as to what to try next.

[scottly]

Did you verify if the coil mounting brackets are positioned properly?

[Bankerdanny]

Did you verify if the coil mounting brackets are positioned properly?

As far as I know it is. I'll take a look at my buddy's bike tomorrow to see if my setup matches.

[ekpent]

  Wish you were closer as Sean or I would plop a whole new coil set-up on it real quick to check. Don't have a spare unmolested stock set around ? Maybe rob your friends for a check. No power then at all to the 2/3 points ?  Hmm, it has to be something fairly easy I hope.

[scottly]

If the 2-3 coil worked with the 1-4 points, the coil isn't the problem. Is there no spark at all?

[ekpent]

Handy time for a meter or test light down there on the points.

[seanbarney41]

iirc, the bracket can be mounted to the frame upside down with the coils still right side up, which causes the bracket to interfere with the primary wires on 2-3...that was a problem I had that was very hard to catch.  Especially, since primary wires are insulated you don't suspect the problem.

[scottly]

Danny, remember Matt's bike at Dolores? The wires at the points were hooked up in the wrong order with the insulators on the screws, grounding the coil wire.

[scottly]

Sean, the brackets have an off-set of the post where they mount to the frame. The front mount is offset to the left, and bolts onto the left side of the frame, while the rear is turned so the off-set is to the right. Note the relief on the front bracket faces to the rear.

[Bankerdanny]

Fortunately I have buddy's F3 with the original ignition setup to look at for reference

[scottly]

The coil bracket is probably not the issue, since the 1-4 points fire the 2-3 coil...
Poke your meter + probe into the 2/3 connection at the coil end, with the negative probe grounded. You should read 12V when the points are open, and zero when they are closed. 

[seanbarney41]

Sean, the brackets have an off-set of the post where they mount to the frame. The front mount is offset to the left, and bolts onto the left side of the frame, while the rear is turned so the off-set is to the right. Note the relief on the front bracket faces to the rear.

yeah, no idea what I did wrong, as now that I look at your pictures there are dozens of wrong ways to assemble that I am seeing, if you take all that stuff completely apart

[Deltarider]

What bike? This is what I'd check at the breakerpoints 2+3:
After first checking the yellow wire's fork connector does not accidentely ground, disconnect for the moment the yellow wire from the 2+3 breakerspoints.
IGN is switched off. Now connect one probe of an ohmmeter to ground and the other to the tiny bolt at the back of the breakerpoints 2+3. When points are closed, meter should read 0, provided the point surfaces are clean.
When points open, meter should read 1, meaning infinite. If there's still some continuity, breakerpoints have to be inspected for a possible problem with the insulators. One of them is a minuscule one in the middle, in the center. It is there to insulate the little bolt. It's a real tiny one and sometimes it is not in the right position. Not often, but it can happen!

[Bankerdanny]

Deltarider, '76 750F.

Here's where things stand. I double checked how everything was attached at the coils against my buddy's unmolested 750F3 and all the wiring is the same.

When the 2-3 points are open I have power all the way to the coil. There is some voltage drop (12.7 at the battery but 11.7 at at the coil), but the blue 1-4 wire shows the same voltage drop and it works fine.

Just for the hell of it I swapped out the front bracket as I had made some relief cuts in the original when I was trying to fit up Accel coils last year. No change.

I did note that when I turn the key off and let it sit for a little while then turn it back on and hit the start button my test plug has a weak spark at the 2-3 leads, but it only lasts a second or so, then there is no more spark. Could it still be a bad condenser? I will try swapping the 1-4 condenser over to the 2-3 circuit and see if that makes a difference.

[Bankerdanny]

As best as I can tell everything is connected correctly. The points and condenser wires are attached to the points in the same way as on my buddy's bike, which has spark at all 4 plugs. I swapped the 2-3 condenser from the other bike to mine and still no spark. I am really at a loss here.

[Kevin D]

Danny, how old are your spark plug caps? What did they measure? Go out in the dark with your bike and a mister bottle and spray them plug caps a bit. See if there is any blue sparking going on.

[Bankerdanny]

Kevin, the plug caps are about 18 months old and have at best 2k miles on them. I tested them yesterday and they all measured within 10% of 5k ohms, so they are in good shape.

[Kevin D]

Kevin, the plug caps are about 18 months old and have at best 2k miles on them. I tested them yesterday and they all measured within 10% of 5k ohms, so they are in good shape.

All sounds good Dan, but still, something is not good. an ohmmeter wont pick up a cracked cap but a spray bottle will.
Are the spark plug insulators clean as a whistle?
You dont have the dreaded Daiichi condensers do you? with the flower?

[scottly]

He had a good spark with the 1-4 points connected to the 2-3 coil, so the problem has to be on the points side of the system.

[Robbo]

As best as I can tell everything is connected correctly. The points and condenser wires are attached to the points in the same way as on my buddy's bike, which has spark at all 4 plugs. I swapped the 2-3 condenser from the other bike to mine and still no spark. I am really at a loss here.

Swap out your 2-3 coil and spark plug wires with your buddy.

Try his set on yours.  If his works on your bike great.  Now just as a confirmation, try your set on his bike.  If it fails to work on his too, replace your entire 2-3 set and ride on .


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[scottly]

- When I swap the blue wire from the 1-4 points into the yellow wire into the 2-3 coil I get a nice fat spark, so the problem would seem to be the 2-3 circuit.

It is NOT a coil problem!

[scottly]

The coil bracket is probably not the issue, since the 1-4 points fire the 2-3 coil...
Poke your meter + probe into the 2/3  primary connection at the coil end, with the negative probe grounded. You should read 12V when the points are open, and zero when they are closed.

[RickThomas]

Given that you've done the troubleshooting and narrowed it down to the points side (assuming temperature is not an issue such as a coil failing when warm) and that the ignition system is set to spec, there are a couple things I would look for:
1: Verify quality components as pointed out by others. (TEC is my go to for the points, condensers, and plate.)
2: Verify that the wiring and fiber plates are connected properly on the plates.
3: Verify properly functioning points by swapping with a known good set.

[Kevin D]

He had a good spark with the 1-4 points connected to the 2-3 coil, so the problem has to be on the points side of the system.

Sorry, I have not kept track of the swaps.
I just dont like it at all when the CB does not run right.

[scottly]

The simple voltage test will prove out the points themselves. I betting on #2.

[Bankerdanny]

Ok, it appears that I have fixed it, although can't swear I know exactly how I did it. I confirmed that I had power completely through the 2-3 circuit to the coil, but still no spark.

I went to O'Reilly and got a points file and dressed the points. Then I removed the bolt and all the washers and gave everything a good clean and made sure everything went back in the correct order (which they already were when I took them apart). Then I carefully reassembled and made sure all my gaps and timing were still correct.

I put the tank back on and started it. I could tell from how it rev'd I had all 4 this time, but to be sure I grabbed some water from my apartment, started it again and let it run for a bit then poured water on all 4 pipes and got a nice sizzle and steam.

I did a short ride around the block and it ran ok, but not great. However, the gas is old and it hasn't run consistently on all 4 for 11 months, so it likely needs gas and a good ride.

Before I do that it needs the headlight reinstalled, which I am working on now. I am also replacing the halogen sealed beam with an LED I ordered this week. It was much easier to adapt to the stock housing than the one in my 550. It is overall thinner than the bulb that was there, so I should gain a little space in the shell.

[ekpent]

 Points file might have been a good thing. I have had dirty points that did not work right on new projects so I always clean and hit them with a file nowadays during first start up prep. I would change the 2/3 plugs at least if the bike has not been firing on those as they may be pretty fouled out getting gas and not burning it. Glad you got her going as summer is definitely here - vroom vroom

[Deltarider]

Some use a business card to 'clean' the points surfaces and then, surprise, surprise the bike won't run on all four anymore, due to the paper pulp on the surfaces. Also that inner minuscule insulator may have been shifted somewhat... but enough for that little bolt to ground. You can look for days for these things.

[Bankerdanny]

Got it out for about 30 miles. Very early in the ride, about 10 miles in, when I was on the highway it started to act up again, I pulled off and started to head back, but after a couple miles it was running fine, so I changed my route and did another 20 and it performed perfectly.

I did order a set of OEM Honda 2-3 points and I also tracked down a couple more points plates in my parts stash today, so if it acts up again I will have some options.

[PeWe]

Intermittent issues like that can also be caused by a bad connector crimp. Move wires and resistance will be lower to later become higher due to corrosion when sitting.
Squeeze the point plate wire connectors with a plier.

I should order a new complete plate.
Even a new Daiichi plate is better than old intermittently failing one that might cause engine issues.
The condensors on Daiichi did not live that long on my bike in the 80's.

Here a nos plate for not as much as others sell them for.
Photo show TEC.
https://www.ebay.com/itm/392792342531

[low-side]

IMO, it sounds very likely that your 2-3 coil is breaking down at higher temperatures.  Getting spark back again after a brief cool down period, combined with all the other tests and inspections you've made, is what makes me think that.  Good luck with it, mystery problems like that are nasty.

[PeWe]

That kind of bad coil behaviour has been described not long ago, Hondaman.