Topic: 1974 CB550 - Odds and Ends

[TPIGroove]

Howdy everyone. I'm still restoring my bike, working towards getting it running. Was hoping to hit that point this weekend, but car problems hit and those are priority unfortunately. Hopefully by next weekend I can see if my carb rebuild went well.

In the meantime, I'd like to clarify a few wiring questions. The bike came with no taillight or turn signals, but I've managed to source those pieces. I'm just curious exactly how everything hooks up, I've got a picture of the wires hanging out the back attached, plus a pic of the taillight's wires. I know the turn signal brackets have wires on them separate from the signals, and I know brown is the brake light. I also would like some info on how the fronts hook up electrically.

Another issue I noticed when I get as replacing the throttle cables was this green wire detached from the started switch. Where exactly would I put it? Does it solder on a spot near the yellow wire?

Last issue is the clutch/brake switches. I need to get a proper master cylinder on there (previous owner put some junk sportbike cylinder/lever on) but I'm curious about how these attach. The clutch one looks broken off as well. Any info you guys have would be appreciated!

[Flyin900]

Download the shop manual from the forum ( Manuals and Technical documents section at the top) and use the wiring diagram from the reference points you need to get everything wired up properly. The front signals have a solid light blue and a solid orange for the left and right units, the additional second wire only on the front signals also use a light blue and orange but with an additional white stripe on these wires. These striped wires are for the running lights function on the fronts only.

The taillight has three wires a green ground wire, a brown wire with a white stripe and a light green wire with a yellow strip from what I recall. The brown striped wire is for the running light part of the taillight and the other light green and yellow striped wire is for the brake light

The rear signals only have a solid orange or solid blue wire as they only run signals back there and no running lights on the back signal light section.

You may have buggered up that clutch switch on the left hand lever, as shown in your last picture, as it may or may not go back together. That little switch is so you can pull in the clutch lever and start the bike while in gear with the clutch pulled in.

That black wire in your rear fender has no business being there. Someone may have done some creative wiring, or you pulled through a incorrect wire. Black wires normally carry 12V + and power various sources throughout the bike.

That green and red striped wire broken off in your switch (light green wire with red stripe is part of the neutral light circuit) It does not show as a colour of wire that should be inside that switch. Someone may have spliced it into the wiring circuit, so trace it back to its source.

[Kevnz]

The rear light has 3 wires going to it, 2 have bayonet ( bullet) connectors, the 3rd ( earth) has a spade connector. There will be a spade connector on the body of the lamp, the other 2 have wires coming out. I think there is only 1 wire each to the indicators ( if they don't have running lights) and there will need to be a separate earth wire as the indicators are rubber mounted. The earth just uses an eyelet on the bolt that secures the lamp to the stalk, and there should be little tabs on the underside of the fender to secure the wires. These earth wires connect to the main loom under the seat after coming up through the grommet in the plastic fender. The earth for the front indicators is part of the nut that secures the indicators through the headlight shell and should have a tab with a green wire to go into the main wiring loom, 1 for each side.

[TPIGroove]

Haven't had many chances to look at it this week, sorry for the slow response. I'm going to try to chase the black wires this weekend if I'm able to. Beneath the fender I found two chewed-up wires, I think they're the original turn signal wires but it's hard to tell with the faded colors. I'm not sure if the black ones are re-wired for those or not, I'll find out. Seems like the taillight wires are okay, though. This bike had a fairing, saddlebags, the whole works on it at one point so that might be the reason why it's like this.

Another wiring question I have: I was going through the electrical panel on the side (replacing crusty components and whatnot) and I noticed at the back is a disconnected ground wire. It has the same connector type as the regulator, but was located further down the harness, coming out with the starter's two wires. Is it an extra, or was it intended for a component? I couldn't see anything for it to connect to, all the components were on the panel and wired up (before I got to it).

One last thing for now, about the airbox. I have the vent line from the crankcase hooked up properly, with the air going through those filter screens before hitting the normal air filter above. My only concern is the foam filter material, will a lawnmower engine filter suffice? Are you supposed to soak it in engine oil, then squeeze the excess? I have the rubber seals for it, I just want to make sure I have a suitable filter before I put everything together.

[Flyin900]

It looks like there have been many wires that have been hacked into and different coloured wire added willy nilly.
Use the wiring diagram as I suggested from the shop manual, so you can see what the original colours are and trace them from there. The colours I noted in my first response are correct for the Honda original wiring colours. It is impossible to guide you without being there to see what the PO has done in the creative wiring department.
 
Non of those colours on the chewed up wires are correct Honda colours for signals, so again look at the wiring diagram to see the correct colours for each component.
The green wire down the harness near the starter solenoid is likely the extra wire that is part of the flasher relay system, which only uses two wires to work. I believe they are a solid grey and black connected to your flasher relay.

[TPIGroove]

Just did a quick continuity test on the rear wires before I go to work. The two black wires are the turn signal wires (orange and blue) while the mangled wires are the grounds for some reason. I'll just re-wire those with a better color.

[TwoTired]

One last thing for now, about the airbox. I have the vent line from the crankcase hooked up properly, with the air going through those filter screens before hitting the normal air filter above. My only concern is the foam filter material, will a lawnmower engine filter suffice? Are you supposed to soak it in engine oil, then squeeze the excess? I have the rubber seals for it, I just want to make sure I have a suitable filter before I put everything together.

There are three hoses going to the air filter system.  From cam cover to lower side of air filter chamber,  A drain hose from bottom of filter box to just ahead of the swing arm, and an air plenum drain hose that also routes in front of swing arm.

The molded plenum drain hose has a reduced diameter, to restrict and minimize air inrush/filter bypass and has a bit of foam inserted to stop bugs from making nests inside.  IF the carbs overflow, this hose keeps the plenum from filling with gasoline and dumps it on the ground for all to see.  Not that that ever happens...

The bottom drain hose has a cap with a split in the end.  At service intervals you pinch this to drain out oil and condensate.
 
At the top of the separator is a foam sheet/filter to keep bits from being ingested into the carb intakes.  If you can find foam thin enough to fit there, small engine lawn mower replacement foam should work fine, and be gas/oil resistant.  It needs to be an open cell foam.  No need to oil it. Dry is actually better but it will soon get soaked with oil vapor and condensate every time the engine warms ups.  Needs to be cleaned at service intervals.  If you drive when its cold and you find milk shake on your dipstick, the foam is likely clogged up and not ventilating the crankcase properly.  Especially if your cold weather runs times are too short to vaporize the condensate in the engine.  As I recall, there is a drawing in the Honda Shop manual supplement showing how the set up functions.  All my bikes have this crankcase recirculation system working, though I don't think you can get the molded hoses from Honda anymore, and you need to be creative to supply a working substitute.  Not too hard when you understand how it all works and functions.

Cheers,

[Kevnz]

SOHRon's excellent article on 550 assembly has a good explanation of the aircleaner setup and photo of the layout.

[TPIGroove]

The hoses weren't the issue, I was just concerned about the filter material. Most of the hosing was okay, just had to get creative with one of them. Biggest issue was removing all of the rust on the metal grated filters, but a soak in evaporust took care of that easily.

[Deltarider]

Do yourself a favour and abandon that breather connection altogether and reroute as shown in Fig. K2-1, p 170 in the Shop Manual CB500-550. Plus: no longer contaminated air filter elements and you can top up the oil again to the maximum mark. Against: nothing. That breather idea was poorly designed for the CB550. Overhere it was a known troublemaker. If you insist on having it, do not top up oil to the upper mark on the dipstick, but maximalhalf way both marks and then hope you're lucky...

[TwoTired]

I’ve been using the the breather system Honda installed on my 550s beginning 1975.  NEVER had an issue with keeping the oil topped up.  And if you ride in cooler climates, the rebreather helps keep water out of your engine and works faster than simple atmosphere dump.

There is also the issue of having the engine burn the carcinogenic oil and piston ring blow by hydrocarbons expelled from the crankcase rather than just venting them to atmosphere for all mammals to breathe in deeply, and also turn the air yellow.  But, if you wish to be the ultimate rebel, you’ll simply ignore what’s best for others, in favor of your own selfish laziness and headstrong ideals.

You are doing both yourself and others a favor by keeping the rebreather functional.

 The Honda system provides the only escape for crankcase carcinogens to be via the combustion chamber where they are chemically altered.

I find it hilarious that a person(s) with no engineering skills would declare the Honda system “poorly designed”.  And simultaneously present no supportive data to corroborate that opinion other than the unwillingness to maintain it.  Thanks for the laugh.

[Little_Phil]

Should we all stop using our bikes and cars that were made before this system was introduced then to protect the mammals?

[Deltarider]

I’ve been using the the breather system Honda installed on my 550s beginning 1975.  NEVER had an issue with keeping the oil topped up.  And if you ride in cooler climates, the rebreather helps keep water out of your engine and works faster than simple atmosphere dump.

There is also the issue of having the engine burn the carcinogenic oil and piston ring blow by hydrocarbons expelled from the crankcase rather than just venting them to atmosphere for all mammals to breathe in deeply, and also turn the air yellow.  But, if you wish to be the ultimate rebel, you’ll simply ignore what’s best for others, in favor of your own selfish laziness and headstrong ideals.

Good day to you, TT. Always good to have you on, mate. You are very concerned about the environment. Don't we know it? You even go to the sky in your plane to patrol the planet.

[...] The Honda system provides the only escape for crankcase carcinogens to be via the combustion chamber where they are chemically altered.[...]

Please inform us some more. Please realise that we, unlike you, were not born with that knowledge.

I find it hilarious that a person(s) with no engineering skills would declare the Honda system “poorly designed”.  And simultaneously present no supportive data to corroborate that opinion other than the unwillingness to maintain it.  Thanks for the laugh.

It is as hilarious as the world wide web where anyone can present himself as an electrical engineer when  that person for a living has been repairing but fans and hairdryers. The opposite is also possible that someone chooses to be modest and NOT brag about education, who knows. In Holland modesty is a virtue. Look, most of us don't know each other, have never seen each other. And as far as the breather system, you can tell the engineers at Honda Germany and Honda The Netherlands their advice has been DEAD WRONG!!! Hasn't that always been your favourite expression? FYI, the matter has even been documented, but it is German. Do you read German, TT?
Another thing. Please, you have to excuse me; my memory is not as good as it used to be. Maybe you can inform the community here who the author was of:
 

You never want to overfill the crankcase with oil.  Crankshaft windage can pick it up and cause it the foam. (also tossing it out the breather tube.)  Better to be half way between marks than over fill it.

[TwoTired]

You are very concerned about the environment. Don't we know it? You even go to the sky in your plane to patrol the planet.

Quite in line with your uninformed demeanor.  I sold the plane years ago.  So, more irrelevant conjecture, intended to deflect, as expected.

[...] The Honda system provides the only escape for crankcase carcinogens to be via the combustion chamber where they are chemically altered.[...]

Please inform us some more. Please realise that we, unlike you, were not born with that knowledge.

Not born with any knowledge.  And there are those that never gain relevant or objective knowledge over that which supports their whims, do you DR?
But, if you noticed, Honda exemplified the process in chapter 8 of the Cb550 Honda shop manual which you've claimed to be familiar with in other posts.  Maybe not, since it doesn't support your desire to avoid maintenance or doing something beneficial to other's health.  Or, it is it you are unaware of combustion being a chemical process?

In Holland modesty is a virtue.

Gee, I thought you might partake of that...  Guess not.

And as far as the breather system, you can tell the engineers at Honda Germany and Honda The Netherlands their advice has been DEAD WRONG!!!

Assuming you are actually providing something factual, didn't they effectually say that Honda was dead wrong?  Wouldn't have anything to do with National commerce would it?  You, know being all modest like.

Do you read German, TT?

I don't believe I've had the urge to read German since the end of WWII.  What's funny is that I own two German made cars.  Ha! One I like far more than the other, though.

You never want to overfill the crankcase with oil.  Crankshaft windage can pick it up and cause it the foam. (also tossing it out the breather tube.)  Better to be half way between marks than over fill it.

Shall we now take all comments out of context?  Or, are you simply unable to grasp the rudimentary concept of not overfilling the crankcase?  An adequate and full oil supply is always the desired goal, especially in hot weather.  Do I want to routinely run the engine a half quart low.  No.  And that was never implied in the quote you desperately purloined. 

[TwoTired]

Should we all stop using our bikes and cars that were made before this system was introduced then to protect the mammals?

Ah, a rebel extremist?  How about we reroute that breather pipe up just in front of your head, too?  Since it is so harmless?
You know, you are a mammal, too?  Do you routinely ingest carcinogenic poisons intentionally?   Is more better?  Is it better for others?
Many poisons are cumulative.  If you are altering your bike to produce more than intended, please stop.  We'll all breathe easier.  And you CAN fairly easily adapt a more modern system to your bike.  You know, like LEDs, electronic ignition, new forks, tires, oil, m units and so on.  Why is modernizing a rebreather system to improve life and your engine longevity, such a distasteful proposition?

Anyway, one goal is to reduce engine pollution, if you are fighting that, then nothing I say will change your mind.  Fortunately, the polluting engine population is getting smaller, particularly with antiques.  If you won't believe lower engine pollution is a good thing.  No real point in arguing.  If you are a purist that just wants a perfectly restored bike for show and sales, you aren't going to be operating it much anyway, which effectually reduces pollution, too.

Ride safe!

[TwoTired]

…You know, like LEDs, electronic ignition, new forks, tires, oil, m units and so on.  Why is modernizing a rebreather system to improve life and your engine longevity, such a distasteful proposition?

Hey now! What’s wrong with mUnits? 

Hi Cal!  Hope you are doing well.

Other than I find them unnecessary for me - nothing.  The point is; upgrading the machine to and with modern components seems pretty widespread, even popular, from reading this forum. So, why not the modern improvement of a crankcase positive breather?  Even some Germans found them useful/beneficial, as both my German made cars have that incorporated.  I suppose DR will say that they were the "stupid, ignorant" Germans.

If DR's report that some German engineers found issues with the Honda rebreather, why did they favor eliminating it altogether instead of applying their superior brain to making it work acceptably?  Did they simply ignore the noxious gasses that emanate from the crankcase breather tube and call it "fixed"?

Could DR simply have hated the rebreather and then sought supportive opinions to make his choice seem righteous?  Just what is it that makes engine vapors dumped into our breathable atmosphere a good thing?

Cheers,

[Deltarider]

I’ve been using the the breather system Honda installed on my 550s beginning 1975.  NEVER had an issue with keeping the oil topped up. [...]

And because you never had an issue, you prefer a foam air filter over the genuine Honda cellulose one, you, the person, that even wants the Honda brand oil in your bike... If you don't mind me asking: what do you know, that Honda developers didn't?

[...] There is also the issue of having the engine burn the carcinogenic oil and piston ring blow by hydrocarbons expelled from the crankcase rather than just venting them to atmosphere for all mammals to breathe in deeply, and also turn the air yellow. [...]

Why concentrate on the fumes? I don't know why US legislators made the system mandatory, but overhere concern has always been about the oil spillage that goes with it, which oil tracks make conditions dangerous for all driving eventually, but almost immediately for twowheelers. So far I have not seen mammals dying on the spot of blow-by gas. They do die in the hunting season, but from blow-by gas? Really? And I myself, who for the last 40 years have been riding a bike with the vent open right under my mammal but, am doing fine. Whereas there are many that have died on the spot, right after encountering oil on the road and it doesn't take much accumulation either... 

[RAFster122s]

Someone's panties got in a twist...maybe it will wring some of the #$%* out of them. If DR was given an enema he would fit in a shoebox, or is it a matchbox?

[TPIGroove]

Yeah, that's enough of that. If I have another question I'll bring this thread back.