Topic: Easy Questions (Hopefully)

[Paul E.]

Lots of questions, so this might get long...

I recently purchased a '74 CB550 (my first bike ever) with 17,000 miles on it and was feeling pretty intimidated by fixing it up but luckily found this awesome website.  I cannot even begin to describe how many helpful posts I've read over the past few days!  My Clymer manual is in the mail, but until it arrives this forum has answered just about every question I've had.  Although for some reason I am unable to track down the bike's identification using the numbers present on the steering tube (1011786) and the engine (CB550 1011721)! 

**Disclaimer** If any of the terminology I'm using is incorrect, please let me know.  Everything I've picked up has been inferred from other posts.  So I could very easily have misinterpreted something.  I think the Clymer manual will definitely help with that!

Ok, so when I bought the bike the rightmost exhaust was not getting hot to the touch as the other three.  The P.O. suggested I take the carbs apart and clean them and see if that resolved the issue.  While unhooking what I believe was the breather hose there was a good amount of gasoline inside it.  Is it supposed to have gasoline it it???  Here's a picture of the hose that I am talking about.
 

I wrestled the carbs out and started cleaning each one individually.  I wiped the floats, float bowels, and gaskets down with kerosene, soaked the slow jet, emulsifier tube (?), float needle, and float needle pin in carb cleaner and then sprayed cleaner insider each carb and shot compressed air out of it.  I wasn't sure how to remove the brass rod inside the tube that holds the main jet so I left it alone.  I didn't replace the float gasket o-rings since they seemed to be in pretty good shape.  Or should I go ahead and replace all the rubber pieces in each carb?  I'm not sure how often they should be replaced...  Was this a pretty good cleaning or did I miss anything major? 

Here's a picture of the stuff I wasn't sure how to access or clean beyond spraying carb cleaner and compressed air.  I am not sure what the brass tube sticking out perpendicular to the slides does/controls.  So if someone could enlighten me that would be great!  Oh!  Should the slides be able to freely slide up and down?  I watched a video on carb cleaning by Mr. Max Storey and the he was able to move those slides with one finger.  I definitely can not push them up as easily if at all!
 

And to clear up terminology:
1. Main Jet (pressed in place)
2. Slow Jet (screwed in)
3. Float needle holder (pressed in place)
4.
5. What are the two holes located on either side of the main jet?
6. What's the story on the red circled screw in the other picture?


On the rightmost carb (the 4th carb?) I noticed a large white deposit on what I believe is the emulsifier tube? located under the main jet (#100).  Could this deposit be the source that causes my problems with the fourth exhaust tube? 


If I cleaned everything that needed cleaning then the next step would be to set the float height at 22mm, right? 

Sorry for the long post, I just have a ton of questions and working on this thing is getting to be really addicting!  Thanks in advance for any help/advice/corrections that I am sure will come!

Cheers,

Paul

[lucky]

That hose is the breather hose from the engine.
It should only have condensation and oily residue.

The two small brass balls showing is where a hole that was drilled had to be stopped up.
Leave those alone.

The circled red screw is your pilot air adjustment. If you look in the venturi you may see how it raises and lowers the slide. remove that and make sure not to loose the spring if it has one. It may have an O ring too. Do not loose that.

[Stev-o]

First off,welcome, you've come to the right place. Second, don't believe everything the seller tells you, your better off believing nothing. 

Your #4 cylinder is not firing, that's why it is not hot like the others. (sitting on bike, #1 is on far left, then 2, 3 and 4, left to right).
Could be a fouled spark plug, I would replace all.
You should also give it a 3000 mile full tune up, that way you have a good base to start from. Also replace the spark plug caps and trim .25" off the plug wires before you put the new plug caps on to give a good connection.

Good luck

[Old Scrambler]

Welcome.......and your off to a very good start. If that was truely gasolene in the breather you have fuel running from an overflowing carb going into the airbox.  That white residue on the emulsifier tube is dried fuel. Be careful when cleaning the brass not to enlarge any holes or scratch the tips on the needles.

When you install your plugs, keep one or more of the old units to check for spark from each wire. That saves time and the threads in the head.   

[phil71]

As for terminology... they're not float bowels.. though, if the bike is sitting long enough, you will find lots of crap in there

[Bailgang]

If you look in the venturi you may see how it raises and lowers the slide.

Huh? Not on 022a carbs. And it would be normal for that hose to have a bit of gas in it because that's it's purpose, it's to drain any gas that may built up in that part of the air box. The problem is that the other end of it shouldn't be hooked up to the top of the valve cover. The hose coming off the top of the valve cover should go to the bottom of the air filter box. http://forums.sohc4.net/index.php?topic=89042.0

[Paul E.]

Thank you for the welcome Stev-o and Old Scrambler!

Replacing the spark plugs and caps makes a lot more sense to me as to the reason why the #4 cylinder isn't firing, but at least I now know my carbs are good and clean as well.  I'm not sure what all a 3000 mile tune up consists of, is there a thread that I could read to find out? 

_Bailgang I think I read over that thread when I first was trying to identify that hose and thought it might be hooked up incorrectly. 

Should the breather hose, #17, be hooked up to #23?  If so, is anything hooked up to the nipple on the bottom of the air cleaner chamber (what it was incorrectly hooked up to before)?

And yes Phil, I did find a lot of crap in there 

[Pat_at_APE]

Hello Paul,

The breather hose from the valve cover (17) connects to the elbow fitting (23) on the lower side of the airbox.  The connection at the bottom of the air box connects to a hose run down to drain any oil that collects (don't oil your rear tire. put it to the side). 

Pat at APE

[Deltarider]

Your float heights are correct. I can see in the picture nobody messed with the tangs (why should he?), so they're fine.

[OneWheelDrive]

The circled red screw is your pilot air adjustment. If you look in the venturi you may see how it raises and lowers the slide.

This is certainly incorrect.  It is the pilot air adjustment, but it allows you to fine tune air mixture at idle by richening or leaning by way of an air passage (not by moving the slide).  You should fully seat each screw (gently), then back each screw out 1 and 1/4 turn. 

If you still have the carbs off the bike, it is crucial you clear the pilot (slow) jet passageways.  Soaking them is likely not enough.  Carefully unscrew them, and pass a high E guitar string through the opening.  Unless you can see a pinhole of light through the jet, it is not clear.  Be careful when you screw them back in also, the brass is delicate and can snap at the base, leaving a nice plug in the threads that can be hell to remove.

While you are waiting for your Clymer, go to the workshop manual download page here http://forums.sohc4.net/index.php?topic=17788.0 and get the one you need.  The 3000 mile tune up is the first 20 pages or so.  Good luck!

[Paul E.]

Ok, so I went ahead and pulled the spark plugs out to see what I was dealing with.  Here's the result with #1 being on the left and #4 on the right.  (The #4 cylinder hasn't been firing.)

And a close up on #4

I think the spark plug wire should be long enough that I can cut 1/4" off the end as suggested.  (I'm making this assumption off the fact that there is a little bit of curve in each wire, so I believe removing some slack won't keep the spark plugs from reaching.)

When I cleaned the brass tubes I was able to see a small pinhole of light in each one and checked to make sure the holes in the sides were also clear.  So I think they should be good to go.

I haven't adjusted the float height yet, it is still set to whatever the P.O. had it at, but it sounds like Deltarider believes they are in the correct position so they shouldn't be adjusted???

And thanks for the clarification about the breather hose.  That makes sense.  I'll be sure to hook it up correctly when I get there.

Wow!  That workshop manual is a big help.  I downloaded a different, more technical one, and between the two feel pretty good about figuring things out. 

Cheers!

[lucky]

Sorry for the mistake on the breather hose connection and that pilot air screw,I thought the 1974 would have air screw.- LUCKY

BTW...Excellent drawing on reply#9 of that link!!

[Bailgang]

Sorry for the mistake on the breather hose connection. LUCKY

BTW...Excellent drawing on reply#9 of that link!!

Just don't let it happen again Lucky, we try to run a tight shift around here ya know?

[lucky]

Sorry for the mistake on the breather hose connection. LUCKY

BTW...Excellent drawing on reply#9 of that link!!

Just don't let it happen again Lucky, we try to run a tight shift around here ya know?

I am learning . LOl..lol.

[Bailgang]

I am learning . LOl..lol.

I'm still learning too, it's just that I've had the 022a's  on my 550 apart so many times I swear I can do it blindfolded.

[SohRon]

Here are a couple of shots showing how that hose routes. As you can see, It's currently backwards in your set-up. Also, don't just rely on the Clymer book. At the very least, download (or better yet buy) a copy of the shop manual as a supplement.

[Stev-o]

Paul - you should be honored as you have just had a special guest appearance in the post above from Ron!  He is currently reassembling one of the most beautiful 550's you will ever see, as evidence is the photos above!

Ron - still impatiently waiting on an update on your thread...

[SohRon]

Paul - you should be honored as you have just had a special guest appearance in the post above from Ron!  He is currently reassembling one of the most beautiful 550's you will ever see, as evidence is the photos above!

Ron - still impatiently waiting on an update on your thread...

  Awww, shucks, Stev-o! You'll turn my head! I'm actually preparing a post covering just this exact stuff; I just need to find (set aside) the time to complete it. Hopefully, this weekend will do it. 

[Duke McDukiedook]

DOWNLOAD THE HONDA MANUAL!!!

Sorry about the caps, want to make sure you do this, Clymer misses stuff and outright gets some things wrong.

[Paul E.]

Wow!  That's a gorgeous set up you have there SohRon!  I am joining the ranks of those awaiting your updates now! 

For the Honda manual, are you are talking about the "Honda CB550 Owner's Maintenance Manual 1974" located here: http://forums.sohc4.net/index.php?topic=17788.0 That seems to contain a lot of the know how I am looking for!

OK!  So I put the cleaned carburetors back on the bike, replaced the spark plugs but left the original caps, changed the oil and oil filter (the oil filter bolt head was a PITA to get off!) and am happy to report that the 4th cylinder was firing!  One thing I noticed about the spark plugs was that:
coil 1 went to plug 3
coil 2 went to plug 2
coil 3 went to plug 1
coil 4 went to plug 4
Is that the correct routing of cables?  Seems pretty weird to me!  But this is my first time so perhaps it is normal. 

It was idling very high at 3,000 rpm and would fluctuate down to 1700 rpm, but thanks to the suggested owner's manual was able to find and adjust the idle screw and get it down to about 1300 rpm.  Any lower and it seemed to idle a little rough.  When I would open the throttle up to 4000 rpm it would start to backfire.  This occurred both when I tried to slowly ease into 4000 rpm or if I quickly opened the throttle to 4000.  I'm not sure what is causing the backfiring or how to fix it.

Since I'm not sure what to do next the plan is to do the ignition timing adjustment, valve tappet clearance adjustment, and cam chain adjustment this weekend.

And there was nothing quite like hearing the bike start up after I had it all in pieces.   

[Bailgang]

Paul - you should be honored as you have just had a special guest appearance in the post above from Ron!  He is currently reassembling one of the most beautiful 550's you will ever see, as evidence is the photos above!

Ron - still impatiently waiting on an update on your thread...

Gee whiz Ron I thought my 550 looked sweet until I saw how detailed your engine is, if you are putting that much attention to detail on the rest of the bike then it's going to be awesome.

[Stev-o]

4 coils??  You sure 'bout that?!!

[Paul E.]

Haha, not at all! I meant to say the four spark plug wires.