Topic: Setting points - extremely weird problem

[jakec]

Setting points on stock cb550. Rebuilt points advance. New battery. All wiring connections good and clean. All spark plugs new. All wires trimmed and boots reseated. Original coils and points. Go to set timing.

Plug 3 only fires on F1.4. Plug 4 only fires on F2.3

All wiring is correct. Swap blue & yellow wire connections so now it’s “wrong.”

Plug 3 only fires on F2.3 Plug 4 STILL only fires on F2.3.

I can see the F1.4 opening. I also don’t have the points upside down or anything.

[BenelliSEI]

Does one coil have HT leads to #1 and #4? The other coils to #2 and #3? You sure?

[jakec]

Yes definitely confirmed that.

[Deltarider]

Did you have the advancer apart and was it reassembled incorrectly? What state is battery in? When in doubt recharge. Cancel headlamp-always-on-arrangement. What plugs and plugcaps? Are the latter firmly screwed on?

[dave500]

if youve taken the assembly apart be sure its been put back correctly

[Alan F.]

Locator pin from advanced to crank is present? They do come loose and go missing.

I know it's kinda obvious but strange symptoms sometimes need simple logic checks.

[jakec]

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.

[Ryan66]

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

[Deltarider]

It is weird indeed. Maybe this vid is helpful.

At the breakerpoints a tiny bit of sparking is normal, excessive sparking or arcing is not good and can indicate a bad condenser. So in this vid the left condensor (1+4) is bad, right condensor (2+3) is good.
And it is always good to ask yourself: what else have I touched (= worked on) lately?
You are not using a stroboscopic timinglight that has a dial, are you?

[jakec]

Thanks for the video. it is not arcing like that. only a tiny arc for both. And I have not been able to get the bike running yet, so this static timing.

Re: what else have I touched, when I noticed that 1 & 4 weren't sparking I swapped another identical coil of a cb500 onto the bike. But it didn't make any difference with the symptoms.

[jakec]

if youve taken the assembly apart be sure its been put back correctly

I did not see the arrows first time I viewed this. I have cleaned up many points advancers before and never knew there was an index mark. I will check that asap.

edit: I just checked and the index mark was off 180*. What effect would this have? I assume it would resolve the issue where I had to cross the blue & yellow wires.

[Menno]

So... are the points new?
Because often points don't wear out between the points but on the carbon part that runs against the points cam.
On the condensators there is a clamp to hold a piece of eh wool(?) (don't know the English word).
This should run against the points cam and should be oiled.
If this runs dry the points will wear really fast losing millimeters on the carbon of the points.
Trying to install them correctly will be unsuccessful.
By new ones.

[jakec]

If I can see the points opening doesn't that negate that theory?

[jakec]

I tested the 1.4 condenser and it was good. I did notice that the condensers were touching so I mounted them to not touch. I also flipped the advancer. I was then able to get a much stronger and comsistent spark and set the timing. So it should be problem solved.

[Deltarider]

I did not see the arrows first time I viewed this. I have cleaned up many points advancers before and never knew there was an index mark. I will check that asap.

See little white frames in pic below.

edit: I just checked and the index mark was off 180*. What effect would this have? I assume it would resolve the issue where I had to cross the blue & yellow wires.

Yes, it would.

I tested the 1.4 condenser ...

How did you test?
Congrats, you've solved the problem,

[Bodi]

"Plug 3 only fires on F1.4. Plug 4 only fires on F2.3

All wiring is correct. Swap blue & yellow wire connections so now it’s “wrong.”

Plug 3 only fires on F2-3 Plug 4 STILL only fires on F2-3."

This is not weird, it's impossible. You have two coils, one for 1&4 the other for 2&3. You state that the secondary (plug) wires are connected correctly although that doesn't matter here. One plug fires on F1-4 and the other on F2-3, you swap the primary (points) wires around and the first changes to F2-3 but the other stays on F2-3... you see the issue, right? Where is the second coil firing from? Nit the wire to the points that you swapped or it would have to be on F1-4.

[jakec]

I think the problem was the condensers were "sort of" touching which was causing the spark to be really weak and inconsistent.

[bryanj]

Condensers touching wouldnt do it, they are both boltedto ground

[Menno]

If I can see the points opening doesn't that negate that theory?

No. Because the height of the carbon on the points is lower you will be turning the points further to the left (or right) to let them open...

[HondaMan]

If the points cam is in the advancer backward, this is what happens.

[Deltarider]

Condensers touching wouldnt do it, they are both boltedto ground

When not paying intention, the forked terminal of a condenser can touch the plate intermittently (for instance via the crosshead 2+3). It is rare, but it can happen. Hard to diagnose.

[jakec]

Condensers touching wouldnt do it, they are both boltedto ground

Well I was able to get the stronger consistent spark and set the timing after doing these fixes in any case. However we went to start up the bike last night and still nothing. We have rebuilt carbs (checked 3 or so times), new battery, fresh fuel & plugs, not set timing. Not sure what can be the problem now.

[jakec]

It reminds me of when I was working on my 400 last summer. Everything was theoretically good to go but it just wouldn't run. Then I bought some new coils and it was good to go.

[goodtryer]

have you confirmed fuel flow?
check that fuel comes out when you open each bowl drain
are the plugs wet?

[jakec]

Yes & yes...

We are having fuel to all 4 carbs. And have seen wet plugs after attempts to start.