Topic: 1974 CB550k Boss Maroon

[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.


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 ?

[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.


Sent from my iPhone using Tapatalk

[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.


Sent from my iPhone using Tapatalk

[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


Sent from my iPhone using Tapatalk

[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.


Sent from my iPhone using Tapatalk

[grcamna2]

How's your key switch ?

[brett_bike]

Since I purchased the bike I’ve replace the stock coils with 5ohm coils, wires and caps purchased from 4into1.com

I’ve also installed a Dyna electronic ignition. I’ve used Hondaman’s Tranzistorized ignition system in the past but I wanted to give the Dyna a try in this bike. I followed directions but rather than use the wire ‘clip’ that snaps into another wire for power I made a 3-way connected with new male/female plugs and added a plug to the brake pedal wire. It has constant power when the key is turned on so I thought that would be fine. The bikes runs well, and the brake light works, just no headlight or taillight.

Since the issue I tried to bypass the Dyna ignition and see if the lights work.

They do not.

As far as the key switch is concerned, when the switch is turned to ‘park’ setting (far right) the tail light (parking light) works.


Sent from my iPhone using Tapatalk