Topic: Help me with my '75 CB550

[speedy_the_drummer]

I know the side cover is wrong, he just threw it in.

The VIN is CB550F1000***

Looking at the title, it was issued in '85 with 21,450 listed. It now says 21,500. So it seems that it hasn't really been driven since before '85... I think it used to be in the hands of someone in the navy maybe? it had some weird navy/army plate tag.

It was fron Va Beach area, so it's a possibility...

[OldSchool_IsCool]

That's prolly the frame VIN.  Check also the motor's VIN.  It should be on the tranny right under carb #4.  It should be similar, maybe differing by a few hundred.

[speedy_the_drummer]

I'll have to check tomorrow after work. The bike's at my brothers garage.

Why would there be a K engine on my beautiful F frame?

[campbmic]

Hey Speedy!

A few months ago I bought a 75 CB550K1 for $200.



The bike turned over freely but would not fire up. After cleaning mud out of the gas tank, tearing apart and cleaning the carbs, new plugs, oil and filter change, and some wiring it fired right up! It ran really bad, sounded like a monkey inside the engine, and ran really poorly.

So I decided it would be fun to tear into the engine and a great learning experience. I didn't order parts until I needed them and because I did this what should have taken me a weekend ended up taking about 3 months. After a new gasket set, new rings, some measurements, and a little head work I got the engine all together. I painted it with Duplicolor aluminum engine paint and it looked great!

I put the engine back in the bike and fired it up. It sounded the exact same! After a few hundred dollars in parts and 3 months of labor nothing was accomplished. One night gas leaked out of the carbs and ruined the engine paint I had spent days perfecting. Sad and depressed I came back to the forums to try and get some answers.

After a few of the great guys here helped me out I set the ignition, tappet clearances, rebuilt the carbs and a few other routine maintenance procedures in the manual. Now it purs like a kitten but I still have a couple more things I need to get right. Anyways, the entire time I was in the engine I was just wishing I could be working on painting the tank, doing the electronics, redoing the seat, or getting gauges. I really kicked myself for breaking into the engine when I didn't know for sure I needed to fix something. I just got to this point where the top end was torn down and I was like, "Great theres nothing really in here thats broken and I've just wasted a lot of time and money".

Anyways if you want to get into the engine this is what I would recommend.

First-
Get shopping and buy;
-A gasket set (I used the top and bottom David Silver Spares one and it is the best and cheapest I could find)

-Four sets of STD piston rings again DSS is the best source I could find

-8 Piston Circlips

-Cam Chain (only needed if yours is out of manual specification)

-650 or 550 Cam (the 650 cam install is popular among 550s it gives you more horsepower, I unfortunately  didnt have the fundage to do this and mine was in good condition. If yours is bad I would go for this)

-Cam Chain tensioner (only needed if yours is out of manual specification)

-Micrometer, Telescopic Gauges, and Dial Indicator


Second-
Start tearing into your engine use my rebuild thread as a guide if it helps
http://forums.sohc4.net/index.php?topic=63687.0
I kind of gave up on my rebuild thread which is a real shame. I would send your head to MReick apparently he can do really great headwork. I don't know anything about valves so I can't help you with the head. Take your engine block to a machine shop and have them measure it to make sure it is within specifications (see manual) and have them hone it. Use your micrometer to make sure your piston is within specification. Measure the Cam shaft for run out and make sure its within specification. If anything is bad buy a new or used one. Put it all together and you've pretty much done a top end rebuild.

I will help as much as I can since I just went through this a few weeks ago.


I really recommend against tearing into your engine. I've made the mistake so if you choose not to I would do the following.

1) Change the oil, and new NGK D7EAs
2) Drain the gas out of the tank make sure it is clean inside. If not ask me or anyone else how to clean it.
3) Take apart petcock, clean, and put back together. If you need a new filter I know DSS sells them.
4) Take off the carbs buy four carb kits at the bottom of this link https://www.partsnmore.com/cat_index.php?model=cb550&category=carb
5) Take apart carbs and dip them in simple green solution. Make sure all passageways are free.
6) Install carb kits and new fuel lines (try autozone)
7) Remove airbox and change out filter (I use pods so I don't know too much about airboxes)
Add gas and try to fire it up!


Heres a picture of the bike now


Lastly, whatever you do DO NOT paint the engine. Use 400, 500, 600, 700 grit sandpaper up to 2500 grit then steel wool then scotch brite red pads. Right now, Im having to scrub off all of the paint and then go through this process!

[speedy_the_drummer]

Hey camp! thanks for all of that! I think I'm going to do the later idea, not open the engine unless I have to.

I just bought these, so I'm on my way!
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=230452283980

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=230461286313

[OldSchool_IsCool]

Well done Camp!  Guess I never saw the final product. 

Speedy, note the forward placement of Camp's kickstand?  That's one of the subtle details that differ between a K and an F.

[speedy_the_drummer]

I see, so mine is an F since the stand is where the frame bend is, right?

[campbmic]

Speedy,

Those are the right sparkplugs. However, the carb sets you ordered are only gaskets. I would suggest you try to cancel the transaction. In carburetors you have gaskets, idle jets, main jets, float needles, floats, and float seats. The gaskets are more or less if your carbs are leaking gas then you need new gaskets. Depending on the state inside of your carbs you may likely need the jets, float needles, and float seats. The floats can also go bad but those are pretty hard to find.

Keep the sparkplug order and cancel the gasket order. Place an order with partsnmore for the carb rebuild kits which will include; gaskets, all jets, float seats, and float needles for $12 per carb =$48. The only thing that you may need after that is floats. To test floats put them in a bowl of gasoline and if they float they're good if they dont float you need new ones.

Little stuff like this sucks when rebuilding your bike luckily I already made that mistake and could tell you before you waste time/money.

[OldSchool_IsCool]

I see, so mine is an F since the stand is where the frame bend is, right?

Unless someone got cheeky with a welder, your frame is an F.  Check the motor VIN to see if it's original to the frame (withing a few hundred).  A K motor will bolt into an F frame (I'm pretty sure).  There are carb differences and the stock exhaust on an F was 4 into 1, not 4 into 4 as with the K.  Side covers, paint schemes, tank & seat differences.  A few more ponies, but not a whole lot.

There is a model guide on the main website here if you want to get the specification differences.

[speedy_the_drummer]

They are out-of-stock...

[campbmic]

Call them tomorrow I ordered some parts through them that were out of stock and it only took a day or two extra. That gasket set looks a lot like a carb rebuild set but it really isnt what you need. Do you have a battery for it? Have you tried to see if the electrics turn on?

[speedy_the_drummer]

I'll call tomorrow. Hopefully he'll cancel the order and let me just get the plugs.

I have a battery for my cl350, would that work just for a tester.

And no, I haven't tried anything really... Going into it blind as of now. (ive only had the bike less than a week with one day of dismantling it)

-actually there's no number to call...

[campbmic]

I guess just email them

orders@partsnmore.net

they are pretty quick at responding. If you have any other questions message me!

[scottly]

Little stuff like this sucks when rebuilding your bike luckily I already made that mistake and could tell you before you waste time/money.

Good show, Mike, to share what you have learned the hard way!!!

[dave500]

get a big plastic tub that will fit the rusty chrome parts in,,fill it with a 50/50 mix of hot water and mollasses,leave it all soak for at least two weeks stirring it occasionally,itll safley remove the rust.,youve got time.

[speedy_the_drummer]

My engine is labeled CB550E-1074018


I also opened up the carbs.... oh the fun is just beginning...



one looks unusable to me, since the metal is deteriorated where the main jet? goes and the two pegs where the float pin goes through. What do you all think?


carb 2


carb 3


carb 4


I also opened this part up... i don't know what these are called. The gaskets on three looked new and one of them looked like the gasket turned into what a rats nest looks like.

I think the main parts that are under these covers aren't moving freely on two carbs like the other two. What can I do about that?

I also cant get the jet? out of any of these. (the big middle one, i got the one flat head jet out of them)

Should i soak them in a carb cleaner for a few decades to get them usable?

[Elkie]

You'll want to completely disassemble, I remember there being felt rings in the top, which carb cleaner will eat.

[75cb550 (kyle)]

Check your vin #s engine and frame . It looks like a 550k! Not a 550f! I dont think fs had fork gaiters or those rear shocks. Just so you dont buy wrong parts.

mine has the fork gators and the same shocks (i think)

it's a '75 CB550F

[speedy_the_drummer]

all those pics and no response?

[campbmic]

Hey those pictures are great they really tell a lot. I would say #1 is deteriorated beyond repair. You could use JB weld to rebuild the main jet holder. However, I would suggest looking into getting a used set of carbs. I believe I saw an entire set on here going for $20.

A few months back I broke off an idle jet (the long skinny one that screws in) into my carb #3 body. I was young a stupid and went to my pick n pull that has a few CBs in there. The guy told me he would sell me a set of carbs off a bike for $180. Me thinking I was getting a steal bought them 

If you want to use them then I would
1. Order those partsnmore carb rebuild kits we talked about
2. Remove everything out of the bottom side of the carb; main jet, idle jet, float, float pin, float needle, and float needle seat.
3. Test the floats in a bowl of gas to insure they float
4. Remove the slides from the top side of the carbs, this is done by removing the second nut in your last picture.
5. Dip the carb bodies and slides in some simple green and scrub the crap out of everything to make them shine like new
6. Blow compressed air throughout the passageways to make sure they are free of debris
7. Install rebuild kits and button it back together

Even if you get another set of carbs you will still need to get the rebuild kits and rebuild them.

Also, in the put the carb boots in some hot water. There is a guide in the FAQ on how to make them soft again. Also, scrub the crap out of the intakes, I would use some sandpaper and work my way up to 2500 grit and they should look brand new.

Good luck and your fingers are going to be hella sore!

[TwoTired]

all those pics and no response?

Pics are more informative when in focus. 
If the carb body is corroded where the main jet sits, the important bit is where the main o ring seals to the carb body tower.  If it can do that the they will still function.
Beyond that, goobered up carbs are pretty hard to assess.  Clean away the goobers and see what the carbs actually look like.  You aren't going to try to run them with all that crap in there are you?

[speedy_the_drummer]

Camp, you are my new best friend.
Which nut in the last picture? I don't know if I'm seeing it.
I will do everything you said and let you know how it goes.

Pics are more informative when in focus.
I know I know... my camera is about 7 years old. I could by a new one, but then I'd have to hold off on parts. Maybe I'll try and borrow a nicer one.

I'm going to try and go to the local yard and see about buying one carb, we'll see how that goes.

Clean away the goobers and see what the carbs actually look like.  You aren't going to try to run them with all that crap in there are you?

I tried cleaning but I didn't want to hurt the floats. So I tried taking the floats out, but 3 of the 4 were stuck.
Also, all the center main jets are stuck. I'm afraid of hurting the carb bodies trying to get everything out.
What is the best way to remove the stuck mains and the float pins without screwing the carbs up? I read heat for the pins. Good idea? As for the jets, I don't know how to grab them without hurting them or the carbs.

Sooooooo many questions, I know. But it's better to ask then to f-up a set of carbs, eh?

[75cb550 (kyle)]

a couple of my float pins were a little stuck. i think i used a very small punch to try and push along with a set of precision pliers... (very carefully). heat could work buti would think that would cause the pin to expand faster than the carb body... im sure someone else knows better than me on this, though.

[TwoTired]

You can clean a lot away by using those aerosol carb cleaner spray cans the come with a red tube.  That chemical will not hurt the floats, and may un-glue some of the parts you are trying to dismantle.

Your camera does focus, as some of the picture is sharp and clear.  It is just focusing farther away than the subject matter we are interested in.
Gotta learn to work the machine, bud. 

Main jets are stuck because the orings conform to irregularities and then harden in place, forming a bit of a lock.  You're going to need new orings anyway so soak the jets in aggressive carb cleaner, and just grab them and yank them out.  Marks on the outside aren't the end of the world, but it's nice if that can be avoided.

You are also going to need to knock out the emulsion tubes under/behind the main jets...carefully.  'Cause the other end is a slide needle metering jet that you do NOT want to damage.

Cheers,

[speedy_the_drummer]

The old thing doesn't like to take picture close up to anything. I'm going to try another camera next time.

So I think based on what you all said, I'm going to clean them with Simple Green, then soak them in carb cleaner and try and remove the parts safely. We'll see how that goes.

As for the really deformed carb, I'm going to replace it. I took it to the local shop and they said I could possibly use it if I was on a killer tight budget. I'm not, so 'new' one it is! They have 7 of these bikes in the yard, all carbs gone except for two. One is missing the carb I need and the other is broken beyond recognition.

Who wants to give* me a carb!?
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*sell at a nice price so I don't have to support ebay!