Author Topic: 1975 CB 550K New Project (Read 3236 times)

oldrider · « **on:** December 19, 2010, 11:10:48 AM »

Well my new project bike is finally in our workshop and I just wanted to share the photos of the bike before I start working on it. When I purchased the bike it had no spark but good compression. We did a quick trouble shoot and got the spark issue resolved and fired up the bike. The carburetor drain tubes started to flood the driveway with gas so we shut it done. My plan is to first rebuild the carburetors, reinstall them back on the bike and see if the engine checkouts before dismantling the complete bike to only find out much latter that I have a bad motor. I'm not sure yet what I want to do with this bike it only has 8700 miles on the odometer and is pretty complete. A full up restoration has crossed my mine but after seeing all the Cafe Racers on this forum I'm leaning hard in that direction.

kck3 · « **Reply #1 on:** December 19, 2010, 12:18:10 PM »

From the pics she looks like a quality bike-would hate to see her chopped up.

BruceDeuce · « **Reply #2 on:** December 19, 2010, 12:27:45 PM »

what kck3 said! But its your bike!

Goofaroo · « **Reply #3 on:** December 19, 2010, 01:58:59 PM »

It looks like you really scored with that one. It's hard to tell by the pictures but from our end it looks like it could be thoroughly serviced and cleaned and be a great looking original bike. If it were me, I would put that one back in service and find a $300 bike to chop up. They are only original once. That's a great find you have there.

That being said, if you decide to chop into it I call dibs on the tank, side covers, and fenders.

oldrider · « **Reply #4 on:** December 20, 2010, 03:54:14 AM »

Thanks, it was a great find one of those being in the right place at the right time deals. I picked this up for $300 and it had the full luggage rack with back rest. I've already found a few issues like the right side top exhaust muffler has a dent in the outer wall that while not effecting the exhaust flow does detract from the restoration value and would need to be replaced. The rims need a completed tune or rebuild not sure yet but the spokes are way out of whack and the rims have some major rust on the spoke nipples. As I progress with the tear done I'll add additional photos and write about findings and progress.

The next step is to break down the carbs and rebuild them, any suggestions on the best rebuild kits to purchase, (manufacture name and supplier). I've been working on cars and motorcycles since I was 16 years old so tackling the crabs is not an issue but knowing which are the best rebuild kits I'll need help with.

Thanks again

Toxic · « **Reply #5 on:** December 20, 2010, 04:31:14 AM »

Geez, you guys that find these great condition bikes for only a couple of hundred bucks, totally amazes me. You won't find that up here in Canada for less than $1500.

Great score, for "no money".

Kong · « **Reply #6 on:** December 20, 2010, 06:33:51 AM »

I'm almost always of the "its your bike, have at it' school of thought, but that bike is in exceptionally good condition and you just might be doing both the world and yourself a favor by reselling it and using something else for your build. There is no doubt what so ever that you can make money (triple or better) on it and that just means more goodies or machinist's time on the build bike (which shouldn't cost any more than you paid for this one).

But .... if not; get it running and ride it for a little while. Get a feel for what it is so you can decide what you want it to be.

ekpent · « **Reply #7 on:** December 20, 2010, 06:48:59 AM »

With that kind of mileage I would not even be looking for carb rebuild kits-most of the aftermarket stuff is junk anyways,waste of money.Just clean up the stock good stuff and maybe buy some float bowl gaskets if needed

I would also keep it as original as possible and look for a beater to hack up.

Duanob · « **Reply #8 on:** December 20, 2010, 08:31:59 AM »

Yeah what Kong said so eloquently. I hate to see a perfectly nice restorable get butchered. Yes I said it butchered. That could easiy be a museum quality piece. You never see a garage cafe build end up in a museum. Wait til after christmas, say february and put it on ebay you could reach $2000+. Put that towards your "build".

oldrider · « **Reply #9 on:** December 20, 2010, 09:09:04 AM »

Again Thanks for all your input your starting to make me rethinking using this bike. I'll get it running and stopping (needs a front brake overhaul) and then ride it for awhile and see what develops. I'll also take ekpent's advise and take the carbs apart before ordering full up rebuild kits. I won't be riding this machine until at least April so I've got plenty of time to take it slow and do it right. I'm sure like most of you guys cabin fever is a killer so working on this project helps to pass the winter months.
Regards

kck3 · « **Reply #10 on:** December 20, 2010, 04:05:26 PM »

Glad to hear you might be keeping the bike stock-she is a beauty. Its hard to find a bike in the condition you have that easily anymore-and someone would pay you some coin because of that if you decide to sell it. Depending on how it was stored, the carbs might not be that big of a hassle. Because it was draining gas out the overflow tubes, I would looks at the floats-could just be your bowls are gummed up and a quick clean of those and you could be on your way. Keep us update, its a great looking bike for three bills.

oldrider · « **Reply #11 on:** December 29, 2010, 01:25:21 PM »

UPDATE on Project. I just got back from working on the CB 550K and found several issues I'd like to bounce off the forum for members input. The Carburetors are off the bike and I opened the float bowls and have never in my life seen such crap. The number 1 craburetor looked like someone mixed coffee grounds with varnish and filled the float chamber.The number 2 craburetor had the same crud but less of it. Carburetors 3 and 4 were ok with craburetor 4 being the cleanest of the bunch. I also found that craburetor 3 has a broken float chamber leaf spring. I will be tearing them down and will let them soak before trying to clean out this crud. Any suggestion on what enviormental friendly craburetor cleaner is best to use on this mess.

I also removed the master cylinder and it requires a complete rebuild. I have to get a snap ring pliers of the correct size to take it apart. I removed the front caliper and the piston seems to be welded in so it soaking over night and tomorrow I'll try my compressed air to see if I can get it to come out. Any suggestions if this doesn't work.

Now the bad news the serial number on the motor doesn't match the chassis serial number. The serial number starts with CB550E and the chassis starts with CB550 and both have different seven digits after the above model numbers. What is the CB550E?
Any suggestions on which is older the engine or the frame.

Elan · « **Reply #12 on:** December 29, 2010, 01:42:02 PM »

Quote from: oldrider on December 29, 2010, 01:25:21 PM

UPDATE on Project. I just got back from working on the CB 550K and found several issues I'd like to bounce off the forum for members input. The Carburetors are off the bike and I opened the float bowls and have never in my life seen such crap. The number 1 craburetor looked like someone mixed coffee grounds with varnish and filled the float chamber.The number 2 craburetor had the same crud but less of it. Carburetors 3 and 4 were ok with craburetor 4 being the cleanest of the bunch. I also found that craburetor 3 has a broken float chamber leaf spring. I will be tearing them down and will let them soak before trying to clean out this crud. Any suggestion on what enviormental friendly craburetor cleaner is best to use on this mess.

I also removed the master cylinder and it requires a complete rebuild. I have to get a snap ring pliers of the correct size to take it apart. I removed the front caliper and the piston seems to be welded in so it soaking over night and tomorrow I'll try my compressed air to see if I can get it to come out. Any suggestions if this doesn't work.

Now the bad news the serial number on the motor doesn't match the chassis serial number. The serial number starts with CB550E and the chassis starts with CB550 and both have different seven digits after the above model numbers. What is the CB550E?
Any suggestions on which is older the engine or the frame.

At least with the 750's, the engine number NEVER matched the frame. But you can search what year the engine was made with the serial number. I believe the "e" stands for engine!
If you use regular carb cleaner, make sure not to spray rubber parts if you are going to reuse. I personally would use good ol' carb cleaner. I think there is much less environmental impact than the oil or gas you will be using! But you could alway try some simple green concentrated.

Do a search on removing the piston. Basically, a grease gun hooked up to the threaded pipe hole and it pops right out every time.

oldrider · « **Reply #13 on:** December 29, 2010, 02:36:13 PM »

Thanks for the tip I found that the Engine and Chassis serial numbers fall into the historic build serial number range for my 1975 bike, so there is no issue with the miss match and you were correct the E is for ENGINE.
1975 CB550 K1
Engine#: CB550E-1029182-
Frame#: CB550-1200005

I also found the thread on using the grease gun to pop the brake piston so thanks again. I'll try this one tomorrow.

oldrider · « **Reply #14 on:** January 02, 2011, 06:09:38 AM »

Update 1/02/11
I've completed the teardown of carburetor 1 & 2 and I thought I'd share the photos of what lurks inside these old negelected carburetors. The body and float bowl have been cleaned and I'm working on the components I removed from them. I'm fining additional parts will be required because of the damage done by leaving them in this condition for so many years.

tweakin · « **Reply #15 on:** January 02, 2011, 07:51:32 AM »

Man those were some snotty carbs. It always amazes me the neglect some of these old bike took in previous lives.

mjstone · « **Reply #16 on:** January 02, 2011, 08:18:42 AM »

One suggestion I have for you:

K&L makes a Float Bowl Gasket that is shaped like the five sided bowl is. Much easier to install than the round o-ring that is in some carb rebuild kits. The round ones are a pain to keep in the grove when assembling them. I got mine from eBay. Can't remember the price of hand, they were pricey but after struggling with the round ones, I think they are worth it.

MJ

oldrider · « **Reply #17 on:** January 06, 2011, 09:59:39 AM »

Update 01/06/11 - I purchased a full set of Honda NOS gaskets and o-rings for the carb rebuild. Now that I'm tearing the carbs down I see I'll require new float valves and seats, throttle valve jet needles, main jets, slow jets and one Float leaf spring.

Is there any one stop shop to purchase all these as Honda NOS parts?

Thanks in advance for your responces.

Oldrider

oldrider · « **Reply #18 on:** February 28, 2011, 09:04:36 AM »

HELP It was finally warm enough to do some work on my CB 550k Carbs this past weekend. I found a broked Float Leaf Spring in one of the carbs and I need to get a replacement. Does anyone know where I could source one of these items.

Elan · « **Reply #19 on:** February 28, 2011, 11:34:50 AM »

Quote from: oldrider on February 28, 2011, 09:04:36 AM

HELP It was finally warm enough to do some work on my CB 550k Carbs this past weekend. I found a broked Float Leaf Spring in one of the carbs and I need to get a replacement. Does anyone know where I could source one of these items.

eek it doesn't look like there is a part number for that piece. I'd head straight over to ebay! Is it something you could just fold yourself out of sheet metal? Its that flat tab in the picture right?

mjstone · « **Reply #20 on:** February 28, 2011, 02:55:49 PM »

Someone here on the forum made one out of an old hacksaw blade, if I'm remembering it correctly. Might post in the parts wanted section and see if someone has an extra they don't need.

MJ

oldrider · « **Reply #21 on:** February 28, 2011, 06:08:06 PM »

eek it doesn't look like there is a part number for that piece. I'd head straight over to ebay! Is it something you could just fold yourself out of sheet metal? Its that flat tab in the picture right?
[/quote]

The tab is slotted and fits down on a boss on the main jet tube. I'm thinking of making one out of brass sheet or some spring steel if I can get some of the ocrrect thickness.

oldrider · « **Reply #22 on:** February 28, 2011, 06:10:05 PM »

Quote from: mjstone on February 28, 2011, 02:55:49 PM

Someone here on the forum made one out of an old hacksaw blade, if I'm remembering it correctly. Might post in the parts wanted section and see if someone has an extra they don't need.

MJ

Thanks I'll check out the parts wanted and do a search on making the part.

oldrider · « **Reply #23 on:** March 08, 2011, 09:48:13 AM »

We'll I spent some time on E-bay and sent emails to several sellers that had misc carb parts listed. I found one gentlemen that had two of the main jet Leaf Springs that I need. I sent him the money and should have them to install by the end of the week.

With the weather warming up in the northeast I'll be spending more time on my project and should have some updated photos by the end of the month.

News:

Author Topic: 1975 CB 550K New Project (Read 3236 times)