Topic: 75 CB550 K - Dead cylinder #3 & 4- fixed 2nd and final(?) time.

[scottly]

Gene, just to rule the coils out, would you consider temporarily swapping the 750 coils onto the 550? PITA, I know, but electrically they are the same.

[scottly]

An afterthought: with the wasted spark ignition systems, the spark on 3 and 4 are reverse polarity, and weaker than 1 and 2. It's the nature of the beast. Measure the voltage at the black/white junction at the coils; if it is low, it may still allow 1/2 to fire, but not 3/4.

[Gene]

An afterthought: with the wasted spark ignition systems, the spark on 3 and 4 are reverse polarity, and weaker than 1 and 2. It's the nature of the beast. Measure the voltage at the black/white junction at the coils; if it is low, it may still allow 1/2 to fire, but not 3/4.

I'll check. Thank you. Didn't know that.

[Gene]

Gene, just to rule the coils out, would you consider temporarily swapping the 750 coils onto the 550? PITA, I know, but electrically they are the same.

If we get to that point I may try it.

Just reading through again before I get my hands dirty.

[Gene]

Battery's still reading 12.45 at rest, but frankly, I think it's not very "live" judging by the neutral idiot light test. Very weak.

B/W at the coils, I'm getting readings of 7+, not 12. Key on, run position. Connections were good but cleaning, dialectic too.

Is this just the m-fn battery? Pulling and charging, tho the tender shows green.

Back in a bit.  Will do the clear tube test today too. Just cuz.

Actually, pulled the battery off the charger when I checked and it read 13. Makes me nervous and this is a gel battery-me using a wet-cell tender. Don't want it to melt.

Trying to see if I can get a better read off the B/W. I may not be grounding it properly. Also changing the 9V in the meter.

[b52bombardier1]

A 12.45 volt reading on a battery is only half of its health. Can it deliver many amps? Only a load test at an auto parts store can answer that question.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

[Gene]

A 12.45 volt reading on a battery is only half of its health. Can it deliver many amps? Only a load test at an auto parts store can answer that question.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

Yeah, and it's brand f-in new. I know that means nothing. Wish I'd saved the Yuasa.

[Jimray23]

Did u use dielectric on the bullet connectors for the coils? If so did u aply it before or after they were plugged in? Either way u should test both sides of the connectors.

Jimmy
1979 kz1000 ltd

[Gene]

Battery is weak, and 7v at coils is a significant problem.

Yes, one would think, if the user had proper knowledge of how to use the damned thing.

[Gene]

I'll probably drop #3 just to make sure everything is in place correctly.  Get back to all on that.
 
Hint.

[Gene]

It's the carbs - gotta be. It's been 3-4 years since I've pulled, inspected, cleaned. I'm hoping it's that simple. 

Thank you all so far for your suggestions and checking in.

Hint 2 - wait for it. You'll laugh your ass off.

[Gene]

dammit. #3 bowl, as it came off.

[FIREBLADE74]

First post!

I'm having the same problem on a 76 550SS, 6800 mi. Except its cylinder 1 that won't get fire, got spark, and fuel in the bowl.

Hope you get it sorted and let us know how.   

[Gene]

H*ckin jet just hanging out, having a party.  BTW - put back in - bike is happy as can be. Question is - why. Did I get distracted the last time I was cleaning the jets, only screwed it in hand tight, forgot, put the bowls back on? Is it going to be a recurring issue? Threads not holding? They're not stripped or crossed - went back in easy as pie.

I should have listened to my gut.

Cal - you're right, 7 is a serious problem but I'm so goddamned stupid with a meter I'm sure that reading was wrong. Everyone else who chimed in gave good advice as well. And I appreciate it. But apparently I'm too stupid to listen to my own, which I told my neighbor, that "I bet I pull a bowl off and there's a gorram jet sitting in it."

For anyone else, if you think you have an idea as to what the issue may be, follow it through first. It doesn't need to be reported, but look. I have dragged members into this that I respect and now I come back with a simple, stupid solution because I didn't take the time to drop that bowl and find the real problem.

I'm not saying it's bad, I'm just saying their time could be used on real problems more effectively.

To all who have commented, I do appreciate it, even you Cal. If I have wasted your time, I apologize- profusely. Have I said that enough?

Now, the real question is, why was it sitting in the bowl? Perhaps I got distracted after a quick finger-tighten. Perhaps I didn't even have it in the right spot, but it didn't fall down because it was held there by tension. Perhaps there is an issue with the threads themselves and the jet can work it's way out (I don't think this is it).

Anyway - going to do a short but reasonable run tomorrow - 20-30 miles - make sure it's solid. For now, I feel semi-confident. Took it for a spin around town. Lots of stops and starts, seems to be right.

I'll close this tomorrow if the longer run works out.

I can't say this enough - thank you and apologies if I have wasted your time.

[Gene]

Did u use dielectric on the bullet connectors for the coils? If so did u aply it before or after they were plugged in? Either way u should test both sides of the connectors.

Jimmy
1979 kz1000 ltd

threw it on before I slammed 'em back in. On the male, like lube.

[Stev-o]

Glad you found it!  There are many instances when what appears to be a major problem is an easy fix that was overlooked.  Did you check the others?

[scottly]

What about #4?

[Gene]

What about #4?

Good point - meant to mention it. The carb bowl screw - left side front  (as you're sitting on the bike) - # 4 carb, was hanging on by literally about a thread. No seal.  Just stupid on my part.

[Gene]

Glad you found it!  There are many instances when what appears to be a major problem is an easy fix that was overlooked.  Did you check the others?

I checked #4 - no problems. Didn't check 1 & 2 since they seemed to be ok.

[Gene]

Glad you sorted the problem out. The only person who wastes my time is me. I invest it into things that appeal to me. Trying to help people appeals to me. Sometimes I do, lots of times I don't. But it still is an appealing challenge.

The only reason I linger on some threads like this is due to the evil curiosity to know the remedy. That's all. I file it all away for use another time, another day. This forum offers much to many. For me, its a great big cauldron of learning soup. 

Still no "like" button on here.  Let this suffice.

Thank you. 

[scottly]

Gene, we ALL love a happy ending!

[Stev-o]

Glad you sorted the problem out. The only person who wastes my time is me. I invest it into things that appeal to me. Trying to help people appeals to me. Sometimes I do, lots of times I don't. But it still is an appealing challenge.

The only reason I linger on some threads like this is due to the evil curiosity to know the remedy. That's all. I file it all away for use another time, another day. This forum offers much to many. For me, its a great big cauldron of learning soup. 

Still no "like" button on here. 

This ain't FAKEbook!

[Gene]

Looks like - at least for now - I have my 550 back. Went on a run down PCH for +/- 15 miles and back, no problems, nice response slowing/speeding up/idling.  I'm so happy to have this bike back - it's a fun ride.

Thanks again, gentlemen.

[Deltarider]

Gene, I had the same thing happening on #1 long time ago. When something is wrong, my routine is always to ask myself: what did I last have my hands on. Problem solved within 10 minutes.

[Gene]

Gene, I had the same thing happening on #1 long time ago. When something is wrong, my routine is always to ask myself: what did I last have my hands on. Problem solved within 10 minutes.

Yeah - I need to listen to that advice. Thank you.