Topic: 1974 CB550k Boss Maroon

[calj737]

Thinking that my rich (1-3) and lean (2-4) issue was due to condensers and/or points I ordered a Dyna electronic ignition.

Hopefully that’s a typo above. Cylinders 1/4 and 2/3 are married with the coils and points. If by some chance you have things mis-wired, your carbs cannot be held accountable.

Just checking…?

[brett_bike]

Thinking that my rich (1-3) and lean (2-4) issue was due to condensers and/or points I ordered a Dyna electronic ignition.

Hopefully that’s a typo above. Cylinders 1/4 and 2/3 are married with the coils and points. If by some chance you have things mis-wired, your carbs cannot be held accountable.

Just checking…?

Nope, not a typo. Although I was it was.

I don’t get it either.


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[calj737]

To be clear, you have the plug wires correctly routed 1/4-2/3 from the ignition, but carbs 1/3 and 2/4 are behaving as "pairs"?

[brett_bike]

To be clear, you have the plug wires correctly routed 1/4-2/3 from the ignition, but carbs 1/3 and 2/4 are behaving as "pairs"?

Correct


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[brett_bike]

What kind of needles are in the bike now?  Do you have pics with the numbers stamped on them?

272304 on each needle. Clip in middle #3 position


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[denward17]

^That's what my new Honda needles are, so they should work good if not damaged.

[brett_bike]

^That's what my new Honda needles are, so they should work good if not damaged.

They were pretty gummed up when I got the bike and opened up the carbs. Would it be possible I got a little too aggressive when cleaning them?  After they spent some time in the ultrasonic cleaner I used 0000 steel wool to take off the remaining varnish.


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[calj737]

0000 steel wool won’t damage them unless you try hard.

Before you unmount the carbs (if you haven’t already) do a little test: petcock off, drain each carb bowl individually into a small clear vessel. Measure the volume. Compare all 4 carbs. Then, turn on the petcock, wait about 2’ then turn it off. Repeat the drain/measure test. Same results? Different between the carbs? This rules out any fuel delivery issues at idle and should confirm float/fuel levels.

[denward17]

Did you by chance measure the needles?

Here was my new ones:

Length:

272304 = 55.85mm

Tip diameter:

272304 = 1.41mm

[brett_bike]

Did you by chance measure the needles?

Here was my new ones:

Length:

272304 = 55.85mm

Tip diameter:

272304 = 1.41mm

55.85 length

1.2 at tip.


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[denward17]

Did you by chance measure the needles?

Here was my new ones:

Length:

272304 = 55.85mm

Tip diameter:

272304 = 1.41mm

55.85 length

1.2 at tip.


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That 1.2 at the tip shows wear, one reasong for richness I guess...(assuming we measured in roughly the same area).

[brett_bike]

Did you by chance measure the needles?

Here was my new ones:

Length:

272304 = 55.85mm

Tip diameter:

272304 = 1.41mm

55.85 length

1.2 at tip.


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That 1.2 at the tip shows wear, one reasong for richness I guess...(assuming we measured in roughly the same area).

As close to the tip without hitting the taper point.

But they all measure the same, and my readings are 1-2-3-4, rich-lean-rich-lean.


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[brett_bike]

I have the carbs off the bike again and confirmed all passages are clear. As well as all  brass parts are clean of debris

While I was working on the bike I checked fuel flow and double checked coils were wired correctly.


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[grcamna2]

Did you by chance measure the needles?

Here was my new ones:

Length:

272304 = 55.85mm

Tip diameter:

272304 = 1.41mm

55.85 length

1.2 at tip.


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That 1.2 at the tip shows wear, one reasong for richness I guess...(assuming we measured in roughly the same area).

I have used pin gauges to measure the I.D.'s of each 'needle jet' (the small nozzle which fits between the carb. body and on top of the emulsion tube)and have found a number of them worn larger from the needle rubbing the insides of that 'jet'/nozzle.
New ones( i.e. 'needle set' )come with a new needle and needle 'jet',noticed a big difference after replacing them.  #16012-323-004 'jet needle set'.  Are these the original carbs to that bike ?

[brett_bike]

Did you by chance measure the needles?

Here was my new ones:

Length:

272304 = 55.85mm

Tip diameter:

272304 = 1.41mm

55.85 length

1.2 at tip.


Sent from my iPhone using Tapatalk

That 1.2 at the tip shows wear, one reasong for richness I guess...(assuming we measured in roughly the same area).

I have used pin gauges to measure the I.D.'s of each 'needle jet' (the small nozzle which fits between the carb. body and on top of the emulsion tube)and have found a number of them worn larger from the needle rubbing the insides of that 'jet'/nozzle.
New ones( i.e. 'needle set' )come with a new needle and needle 'jet',noticed a big difference after replacing them.  #16012-323-004 'jet needle set'.  Are these the original carbs to that bike ?

I have no reason to believe these are not the original carbs to the bike. They are 022A. I’ve also seen 069A carbs on my old 73 CB500.

I’m trying to track down the ‘needle set’ but they don’t seem to be available.


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[calj737]

Only place I’ve seen new needles is here, but they are KL brand not genuine Keihin.
https://www.siriusconinc.com/products/detail/920

Given that you replace all 4, you might be able to equalize the tune across the entire rack.

[Stev-o]

While you in the carbs, confirm that you have genuine Keihin jets too.

[denward17]

I have purchased a lot of parts from South Sound Honda.  I asked Dex (SSH) if he had the needle jet set for my '76 550, he did not, but provided me a list of dealers in the country (US) that show inventory.  Now, that doesn't mean that they could put their hands on them, but worth a shot.

I found mine at a dealer in Iowa, I think they had 5 sets at the time, I was lucky to find 4 from the same dealer.

You could call Dex and see if he could do a lookup and see what dealers have them, and maybe you could piece together a set of 4.

[grcamna2]

While you in the carbs, confirm that you have genuine Keihin jets too.

I hope there isn't too much corrosion at the bottoms of the carb bodies where the main jets fit,and hopefully still a tight connection around the o-rings.
You mentioned using #0000 steel wool;it might help to re-check all the passages and blow all of them out again to make sure none of that very fine steel wool wadded-up inside.

[brett_bike]

Update…

Reluctantly ordered a carb kit from 4into1.com. I wanted to replace the emulsion tube and  needle only, just to check if they may have been my issue. I’ve heard concerns so I only used the parts I wanted to experiment with and kept all other brass stock.

I picked up some used aftermarket 4 into 2 mufflers because the original pipes have a couple holes. I don’t care for the look so I won’t be keeping them but they are ‘hole-free’ and quiet. They allow me to hear things better while I’m getting them bike dialed in. I plan on picking up a Delkevik exhaust over the winter. Would love to get the 4 into 4 but man they’re expensive. Has anyone here heard them? Post a vid if you have and let me know your experience with them.

After putting it back together I went for a 10-15 mile ride and it seems better. Not perfect but better than it’s been. The plugs are now showing all consistent reading…all lean. I’m guessing it has to do with the 4 into 2 exhaust. I played with the air mixture screw and settled at 3/4 turn out and there is not much stumbling to speak of and it pulls strong all the way through the RPM range.


I plan on going through the tune-up process and doing a WOT plug chop over the weekend.


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[denward17]

I installed a set of 4into4 Delkevic. They are pretty  n
ice.  Glad to hear the bike is running better.

[grcamna2]

I installed a set of 4into4 Delkevic. They are pretty  n
ice.  Glad to hear the bike is running better.

Den,your 550 there with that scenery looks wonderful 

[brett_bike]

Little update.

Been stuck at home with covid and thus, haven’t been in the mood to wrench.

Feeling better now so I’ll get back to it. The last ride was just a mellow ride to work and it feels pretty good. I’ll be doing the 3k tune up procedure soon and try to get more riding in before winter.

New issue is after the Dyna ignition install my headlight and taillight doesn’t work, but the brake light works with the brake lever and pedal.

I I disconnected the dyna and ran the wires like they were before and still no lights. So now I need to chase this issue. I hate electrical


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[denward17]

Sounds like it could be fuses?

[brett_bike]

Sounds like it could be fuses?

That’s what I was thinking also. I replaced the headlight & taillight fuses and checked the connector.

I’m sure there is a way to trace electrical issues with a multimeter…I just need to research a bit more.


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