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.


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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.


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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 ?

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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[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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[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.


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[brett_bike]

Spring is here (almost) and I’m able to free up space in the garage to continue working on the CB.

I got the previous issue with the wiring sorted out and detailed in another thread.

I’ve ordered new tires with some input from some great members here and decided on IRC GS-11. I’ve read some favorable reviews and they have the vintage look.

I know I should have looked to a local motorcycle shop and I regret not going that route. When I lived in Denver I had a few great shops and an awesome salvage yard I spent many hours rummy through, I don’t know of any shops in the metro area that would support these machines.

There is a salvage yard south of the twin cities in Jordan but they’re pretty expensive and not super helpful in my experience.

Does anyone living in Minnesota have a shop that they would recommend?


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[brett_bike]

Over the past few days I’ve installed new tires. I didn’t document the process but I can’t stress enough the use of some sort of lubricant to install the tires. I used Muc-off pink wash soap because it idly doesn’t leave residue and it slicks things up great. I used three tire levers and wood clamps to pinch the bead in place. Worked like a charm.

Today’s project was pulling off the cylinder intake manifolds(?) and clean things in preparation for installing new o-rings.  A huge thanks (again) to Hondaman for the hookup.

It looks like there may have been some sort of gasket maker or RTV on one of the o-rings. There appears to be a little corrosion in that location. Thoughts on weather or not that might cause an issue?








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[Dr. Frankenstein]

If those O-rings haven't been changed/aren't new, they're probably hard and need to be replaced. An air leak could hide really well there and cause problems...? That could explain the RTV there that the PO just didn't want to deal with...

[brett_bike]

So I installed the intake o-rings and took it out for a ride. Felt pretty good about everything so I decided to ride it to work the next day.

On my way home it was dark and realized the headlight beam was pointing too low for my liking so I grabbed the bucket to reposition the beam and all power cut out. I blew a fuse.

A mile and a half walk home to ponder my life choices that I am maybe too quickly trusting this bike. I. Will be spending some time making sure the wiring is up to spec, and probably ordering Hondamans fuse box.

Time to dig into the rats nest and track down the issue.

I’m wondering if the hardened sleeve of the wire harness in the second pic is causing an issue.

I’m not too handy with a multi meter so any advice is appreciated.




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[newday777]

Start by cleaning and tightening the barrel connectors in the bucket. They become loose over time and dirt in them causes extra resistance which causes heat(you will find the clear plastic sleeves burnt brown) and blown fuses.

A good thread to read for cleaning up the harness.
http://forums.sohc4.net/index.php?topic=95167.0

Hondaman goes into cleaning the connectors in his new CB500/550 book on bringing them back to life(I just got my copy yesterday). And he recommends using  LPS-1 to spray in the connectors to preserve them after cleaning.
I've bought a couple of his replacement ATC fuse panels and they are worth getting.

Yes the plastic sleeves harden up over time. You can get new sleeves from Vintage Connections.
Many wires get broken inside the sleeve from the pinches at the steering neck area where the sleeve needs to be flexible. With a new fuse in the fuse box( you can use an ACC fuse of the right amp rating for static testing purposes to help find a short while in the shop). Test the harness in the shop by moving the harness with your hands to see if you blow a fuse to find the area where the wires are the problem.
Do you know how to solder and heatshrink repair wires? That is helpful to know if you need to repair the harness wires if a break is in the wires.

[newday777]

The book link and fuse panel are under the Site Sponsors section
http://forums.sohc4.net/index.php/board,134.0.html

[brett_bike]

Book is ordered!  Was looking forward to grabbing it so this was a great reminder.

Also picked up some PVC tubing to clean up my harness.

I tested the continuity of many of the wires today and all checked out. Then I noticed the right blinker wires are cracked and may be causing at least part of the issue. There is nothing else obvious yet, but I’ll keep running tests.

[denward17]

It might be just the way the picture looks on the ground to the fork ear, but looks like it is frayed and about to come off?

[brett_bike]

It might be just the way the picture looks on the ground to the fork ear, but looks like it is frayed and about to come off?

It is. I’m wondering if that may be the, or one of, the issues.


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[denward17]

It might be just the way the picture looks on the ground to the fork ear, but looks like it is frayed and about to come off?

It is. I’m wondering if that may be the, or one of, the issues.


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Could be, either way I would fix it.

[MauiK3]

At that age, there may be many gremlins in the wiring harness. Are replacements available for them?

[grcamna2]

It might be just the way the picture looks on the ground to the fork ear, but looks like it is frayed and about to come off?

It is. I’m wondering if that may be the, or one of, the issues.


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Fix the ground connections.