Topic: New Member - 1978 CB550 carb sync issue. Lean now, and #2 cyl not firing.

[flybox1]

To get 1/4 point correct, you need to rotate the whole points backer plate.
Loosen the three mount screws and rotata so it fires on the 1/4 F mark.  The vid was too far away to see how close you were.
Tighten the three screws when.its right.
 Loosen the two screws for the 2/3 point secondary plate, and get it to fire on the 2/3 F mark.
1/4 is always adjusted first.
Good work.  Keep going.

[Calvin]

To get 1/4 point correct, you need to rotate the whole points backer plate.
Loosen the three mount screws and rotata so it fires on the 1/4 F mark.  The vid was too far away to see how close you were.
Tighten the three screws when.its right.
 Loosen the two screws for the 2/3 point secondary plate, and get it to fire on the 2/3 F mark.
1/4 is always adjusted first.
Good work.  Keep going.

That's exactly how I adjusted it. Not sure why the video uploaded so blurry. Before adjustment, the backer plate was almost out of adjustment. I set breaker point gaps then timed it. Both plates are closer to the middle of their adjustment range now and the timing looks almost dead on. Maybe on line width off maximum on 1/4.

[Calvin]

So after riding it now and testing after redoing the ignition timing, it seems to be running better and starting better, but still at idle when I pull plugs 2 or 3, the idle drops, if I pull 3/4, the bike dies immediately.  Anybody else experience this?

[DaveBarbier]

So after riding it now and testing after redoing the ignition timing, it seems to be running better and starting better, but still at idle when I pull plugs 2 or 3, the idle drops, if I pull 3/4, the bike dies immediately.  Anybody else experience this?

Someone else can chime in if I'm wrong, but I wouldn't say this symptom is indicative of a problem. I'd focus on plug color and how the engine runs under load and at idle.

[Calvin]

So after riding it now and testing after redoing the ignition timing, it seems to be running better and starting better, but still at idle when I pull plugs 2 or 3, the idle drops, if I pull 3/4, the bike dies immediately.  Anybody else experience this?

Someone else can chime in if I'm wrong, but I wouldn't say this symptom is indicative of a problem. I'd focus on plug color and how the engine runs under load and at idle.

I am starting to wonder this now, if this is normal. Before, sometimes #2 wouldn't fire at all. Now, it still seems weaker but after everything I've done I wonder if this is normal for anybody.

Experiments anyone?

Just pull plug cap to #1 at idle then to #2 and see what happens?

[scottly]

So after riding it now and testing after redoing the ignition timing, it seems to be running better and starting better, but still at idle when I pull plugs 2 or 3, the idle drops, if I pull 3/4, the bike dies immediately.  Anybody else experience this?

If the idle drops when pulling the #2 or 3 wires, they are firing, just not as strongly as 1&4. Double check the timing using a strobe, and if the timing is correct, you may need to revisit the carb sync.