Topic: 1977 CB550F. First project.

[Adam77]

Hello all! I've been lurking for over a year, researching what it would take for this project. And now here I am. It took over a year but I found the right CB for me. This forum looks like an invaluable tool for restoring my bike. I plan on using this post to document progress and ask questions (a lot of questions). Hopefully by completion this post will offer some insight for people who are in a position such as the one I find myself in now.

About myself:
I'm a 24 year old college student who has decided to dive into the world of classic motorcycles. I've had a couple of different sport bikes over the past 7 years, and really loved them. My last one was a metallic black 2009 CB600RR. Long story short, after being stolen and totaled, I haven't had a bike for over a year. My tastes changed, and I wanted something 'classic'.

I have many hobbies that I am very passionate about, some of which involve tinkering and getting my hands dirty. After seeing some smooth looking cafe racers, I immediately fell in love with the classic Japanese bike look. Cafed out is still cool to me, but for this bike, I want to keep it mostly stock for a while.

My experience is minimal to say the least. While I enjoy working in the garage (having a Jeep requires plenty of maintenance), I've never tuned a carb, replaced a throttle or clutch cable, rebuild a fork, or trouble shot electrical problems. With that being said, between my Clymer's manual, this forum, and the grand ol' internet, I'm not too worried. I also have a knowledgeable family friend who I could have assist if needed. 

About the bike:
1977 CB550F. ~40,000 miles. The engine is sound and I'm sure any problems it has are quite fixable.

Now, the guy I bought it from was very nice gentleman who has worked on these bikes for years. His garage probably had 10-15 classic 70's-80's Hondas. He wasn't currently riding this one, and needed to sell it. He tuned the carb, changed the oil, and got it running well enough for me to ride over an hour on the interstate to get home after dark (I don't advise anyone do this. My nerves were on edge the entire time).

First day having it at home, licensed, and insured went great. It has a laundry list of things that need to be replaced or repaired (I'll address them in later posts), but I felt safe enough to ride it on the road.

On the second day, the gremlins came out it full force, introducing me to the world of classic motorcycle ownership. Still starting and warming up fine, it got about a mile down the road and started kind of jerking forward periodically while holding the throttle steady. The engine started having a poor idle with the clutch pulled in when coming to a stop. I had to nurse the throttle to keep it running. I decided to shorten my trip to get home in a few miles. It died three times in about 4 miles, when coming to a stop. As I pulled the clutch in, the engine would bog down and quit, forcing me to coast to a parking lot or to the side of the road. Not having the greatest knowledge of starting these engines, I tried a number of things. What worked best was using the kick start a couple of times, then twisting the throttle a couple of times, then using the starter button. I would have to do this routine 2-3 times before it would come to life. I can't remember if I had to use the choke at this time. This happened last week and I'm just now having the time to post.

The next day and since then, it will not run. I can get it to start, but only runs as long as I'm holding the throttle above idle at around 30-70%. It only starts with full choke (obviously) and holding the throttle down to about 50% while hitting the starter button for a couple of seconds. Then it dies immediately after letting go of the throttle. 

This is where I come to you knowledgeable people. I've searched all that I can, but these problems are difficult to trouble shoot for a novice. Hopefully someone can offer some insight. If not then I suppose I'll continue browsing the forums, looking for people who have had the same problems that I have. Like I said, I have a Clymer's manual and know where to look for instructions on the internet on adjusting certain parts, but I just don't know what to adjust yet.

I plan on replacing a great number of parts, some of which I'll be asking about in the future, but for now I want to focus on getting it running reliably.

Here's a look at her.

http://imgur.com/jCUwS9U

http://imgur.com/a0QO0El

http://imgur.com/jKJI5VL

http://imgur.com/aTpkUrq

http://imgur.com/yP0qTv1

[SOHC4 Cafe Racer Fan]

Good looking bike, and great priorities get it running reliably first.  Welcome!

[arncruz]

That's a nice bike to start off with.  Congrats.  Are you restoring or restomod? That was my first motorcycle last year!

[calj737]

Time to pull the carbs fully apart and rebuild them. Your problems described are very normally clogged up jets in the carbs. Easily fixed, but intimidating for the first time.

If you are not OCD enough, remove the bank of carbs from the bike, (drain all gas) and then pack them really well and ship to Harisuluv (member here). He will rebuild/restore them to better than factory perfect. If you can't, then start reading threads and detailing the disassembly. And only buy quality rebuild kits!!! Don't replace the stock brass, clean it.

Also, drain the fuel tank and be certain there's no rust in it, and replace the gas.

[Stev-o]

You might want to check one thing before pulling the carbs - pull the fuel line from the carb and confirm you have proper fuel flow. It the tank is rusty inside (use a flashlight to look inside) it could have clogged your petcock.   
Cal knows these bikes well, but if you rode it home, I'm not 100% convinced the jets are clogged.

[calj737]

You might want to check one thing before pulling the carbs - pull the fuel line from the carb and confirm you have proper fuel flow. It the tank is rusty inside (use a flashlight to look inside) it could have clogged your petcock.   
Cal knows these bikes well, but if you rode it home, I'm not 100% convinced the jets are clogged.

Stev-o, you and I are thinking the same thing, except, that now that he rode it home, I'm betting he has sucked up debris into the carbs and clogged them up. Seller did "tune the carbs enough.." so he could ride it, which probably was under the auspices of "they'll need a rebuild" after sitting for unknown time in a garage.

[callmejarob]

Welcome to the world of classic CB's!  One you have one you will be HOOKED!

Rebuilding carbs is actually super easy if you take your time, have patience, and keep everything organized.  Cal hit the nail on the head. 

How far are you wanting to work on the bike?  Engine rebuild with new chains, tensioners, etc..?

[Adam77]

That's a nice bike to start off with.  Congrats.  Are you restoring or restomod? That was my first motorcycle last year!

I'll planning on just restomodding it. Figured I would leave the full restores to bikes in better condition and lower miles. Plus I'd like to have as modern of parts as possible.

You might want to check one thing before pulling the carbs - pull the fuel line from the carb and confirm you have proper fuel flow. It the tank is rusty inside (use a flashlight to look inside) it could have clogged your petcock.   
Cal knows these bikes well, but if you rode it home, I'm not 100% convinced the jets are clogged.

This sounds like a good suggestion for my case. I know the petcock is old and busted (the part that the fuel line connects to mostly broke off in the hose and the hose is being held on with a hose clamp). The fuel lines are old and cracking as well. I was planning on replacing the petcock and lines very soon. Suppose I'll get to that now.

I've looked in the tank, and it didn't look too bad, but it was during the day and difficult to see deep inside. I'll check it again tonight in the dark. Should I be looking for absolutely no rust or just minimal occasional spots?

You might want to check one thing before pulling the carbs - pull the fuel line from the carb and confirm you have proper fuel flow. It the tank is rusty inside (use a flashlight to look inside) it could have clogged your petcock.   
Cal knows these bikes well, but if you rode it home, I'm not 100% convinced the jets are clogged.

Stev-o, you and I are thinking the same thing, except, that now that he rode it home, I'm betting he has sucked up debris into the carbs and clogged them up. Seller did "tune the carbs enough.." so he could ride it, which probably was under the auspices of "they'll need a rebuild" after sitting for unknown time in a garage.

This sounds very plausible. I'll give the guy who sold it to me a call later and see what all he did when he cleaned the carb. I can believe that my jets could be clogged after a couple days of riding after sitting for at least a couple of years. I believe it was last tagged in 2011.

Welcome to the world of classic CB's!  One you have one you will be HOOKED!

Rebuilding carbs is actually super easy if you take your time, have patience, and keep everything organized.  Cal hit the nail on the head. 

How far are you wanting to work on the bike?  Engine rebuild with new chains, tensioners, etc..?

Are there any go to instructions for rebuilding the carbs on my bike? I think I'm up to the task. I've heard the instructions in my manual don't include my model year. I don't currently plan on rebuilding the engine right away since it does seem to run fine. Maybe next winter.

Thanks everyone

[SOHC4 Cafe Racer Fan]

Take a closer look at the gas in the tank, too.  If it has been sitting for a while, it would make sense to drain the gas tank, and look at the condition of the petcock.  You may have sucked up some varnish or particulate matter in the tank which clogged your carburetors.  IF they were cleaned and rebuilt, you may only need to give them an ultrasonic clean.

[Adam77]

Take a closer look at the gas in the tank, too.  If it has been sitting for a while, it would make sense to drain the gas tank, and look at the condition of the petcock.  You may have sucked up some varnish or particulate matter in the tank which clogged your carburetors.  IF they were cleaned and rebuilt, you may only need to give them an ultrasonic clean.

Yeah I'm sure the petcock could be in better shape. The fuel line can barely hold onto it, so for if no other reason I'll be replacing it. It has fresh gas, but when I check the tank tonight I'll stir it up and look for any signs of particulate floating around.

[Stev-o]

Be sure to buy the right petcock, I belive there were two sizes used on the 550.

I buy fuel line hose locally, get 3/16", fits nice and snug, no clamp needed.

[SOHC4 Cafe Racer Fan]

The petcock for that specific year is part #16950-388-015

[Gene]

I just got through a carb rebuild on my 75 550K, looking at yours they look similar.

This forum helped a lot - especially:

http://forums.sohc4.net/index.php?topic=109136.0

http://forums.sohc4.net/index.php?topic=130323.25

Hunted down by Alacrity. 

As well as this advice from Flatlander: "download the honda manual and the partslist from the site. it may sound over pedantic but comparing the description for the same process in different manuals give you another perspective and maybe some bits of info that one was missing.
and the partslist is the best reference for what parts are supposed to be where. a PO may have screwed things up so best to cross-check if it's all as it should be."

Be patient, be organized, do it right - not like I did the first 2 times going at it - and you'll be fine.

[Adam77]

I took a look in the tank tonight. It looks pretty clean to me. From what I could see there are no big rust spots.

The stock petcock number seems to not be available anymore. While searching for quality parts are there any particular go-toplaces to buy from? Or any ebay sellers who are known for carrying good parts?

I found this, but am not sure what to look for to determine quality.
http://www.ebay.com/itm/HONDA-CB550F-CB750F-SUPER-SPORT-CB550-CB750-CRUISER-PETCOCK-FUEL-TAP-FUEL-VALVE-/291123136587?pt=Motorcycles_Parts_Accessories&fits=Make%3AHonda%7CModel%3ACB550F&hash=item43c84a884b&vxp=mtr

I'll pick up the fuel line from the hardware store or Honda dealer.

Also, should I go ahead and add an in-line fuel filter after the petcock?

Thanks

[calj737]

First order of business is to drain some fuel from the tank and determine what the condition of the gas coming out is like. Does it have debris in it? Does it flow strongly?

The tank may not have rust, but with just a peek inside, you can't really see all the nooks and crannies where rust usually forms (underside of the top, flat spots towards the seat, and around the petcock). If the fuel drains clear, skip the filter. They can create more problems than they solve by impeding flow rate.

Then it's off to dropping the bowls of your carbs (can be done with carbs still on bike). Carefully remove them and inspect the internals. If there's varnish sitting in the bottom of the bowls, time for a good clean (carbs gotta come off).

Make these inspections before installing new fuel line. You want to be certain everything is clean, then replace the line so no debris or grunge gets introduced to the new lines. Post a picture or two if you can, that may help guide you along.

[Adam77]

First order of business is to drain some fuel from the tank and determine what the condition of the gas coming out is like. Does it have debris in it? Does it flow strongly?

The tank may not have rust, but with just a peek inside, you can't really see all the nooks and crannies where rust usually forms (underside of the top, flat spots towards the seat, and around the petcock). If the fuel drains clear, skip the filter. They can create more problems than they solve by impeding flow rate.

Then it's off to dropping the bowls of your carbs (can be done with carbs still on bike). Carefully remove them and inspect the internals. If there's varnish sitting in the bottom of the bowls, time for a good clean (carbs gotta come off).

Make these inspections before installing new fuel line. You want to be certain everything is clean, then replace the line so no debris or grunge gets introduced to the new lines. Post a picture or two if you can, that may help guide you along.

Sounds good. I'll try to find time this weekend and report back. Thanks for the help.

[Adam77]

It's been a few months but I've finally had some time off to work on my bike. Quick update: has been sitting since it stopped running. I pulled the carbs off and began taking a look. Is my carb toast? Number of problems.

Carb 1

Just pretty dirty.

Carb 2

Slow jet doesn't screw in tight. It was unscrewed rattling around the bowl. Trying a different slow jet in there does the same.
It goes in all the way without any resistance from the threads. The inside threads don't look too chewed up. Confused why it's not holding it.

Carb 3

Missing leaf spring on the main jet. Area around needle jet really chewed up. Needle jet doesn't go in all the way, but falls out freely.

Carb 4

The best one. Just a little dirty.

So I need a new spring for the main jet. Is the whole thing junk from the damage to carb 2 and 3?
All of the main jets are 98 and slow jets are 38.
Could clearly see light through all of them.


Thanks

[Adam77]

Does anyone have any advice? Or a suggestion of where I can ask for advice?

Thanks

[riverfever]

Adam I saw this several days ago but wanted some of the regulars to chime in as I consider myself to still be a bit of noob. I'll let others correct me if I say anything wrong.

I don't think the carbs look all that badly inside. Mine were certainly dirtier when I rebuilt them. So carb 1 is a non-issue. Clean it. Not sure what's going on with carb 2 and the idle jet not being tight. I do not know if you could install a helicoil in there or not. If you tried it you'd have to make damn sure that all the metal shavings were removed. Worst case scenario...you pick up another carb body for number 2. For that you can contact James (harisuluv) and he should be able to set you up. Or...look on eBay or post in the parts wanted section. 

The missing leaf spring is no big deal. Some have made leaf springs but that's a part you can find. Again I'd contact James, look on eBay or post in the parts wanted section. The inside of my #4 carb body is very bad in terms of being eaten up. Mine seems to be running fine though. My emulsion tubes also don't snap into place and stay. If I turn the bodies upside down they usually will fall out. The main jet with a good o-ring and the leaf spring should keep all that together. It does on mine. Again...clean carb 4. I don't think you're in that bad of shape Adam.

[Duanob]

Does anyone have any advice? Or a suggestion of where I can ask for advice?

Thanks

The TEch board is your best bet. http://forums.sohc4.net/index.php?board=2.0

Just use this board to keep track of progess.

Those carsb don't look that bad. Do the bottoms first then take the slides and needles out second. Clean them up I use carb cleaner and canned air to make sire all passage ways are clear. get a cut away view of the carbs so you know where they go. It also helps to understand how the different circuits work. Use a K&L carb tool or guitar wires work too to clean jets. Make sure all the emulsion holes are clean, the air mix holes on the pilot jets and main needle jets. There are good how-tos here on setting the floats to spec. When you take the tops off you should check the needle postion and clean the needle with brass wool or 0000 steel wool. Carsb are daunting at first but after a few tries and there will be a few tries, third time was alway a charm for me. It gets easier.

Number 2 carb: compare jets and make sure they are all the same. If the threads in the carb body seem OK. The PO might have tried to install a different pilot jet, same 40 orifice but it was not the same length or thread size. These jets should 28mm in length. My 76 CB550F always had an idling low rpm issue no matter how many time I took them a part and cleaned and checked. I finally found two pilots were not the correct ones. After putting four new ones in it ran like a top. edited: After looking closer at the #2 carb pilot hole, it doesn't look like any threads at all. You may be heli-coiling that hole.

[Adam77]

I looked a little closer today. I still can't figure out why the pilot jet doesn't stay in. Same jet as the rest, and it fits in the other carbs. The diameter of the hole it screws unto seems to be too large. The threads inside the hole don't look too messed up, but I'm guessing maybe a PO screwed in too large of a jet once? I have access to a heli-coil set, so I might try that. Also ordered some new leaf springs. I'll get everything put back together and see if it runs.

My o-rings on the main jets along with any other rubber seal is looking brittle. Should I just get a carb kit, at least for the gaskets? I've gathered that using newly manufactured jets is generally a last ditch effort, and you should always try to use stock. Which brings me to my next question, my manual suggests main jet no 100 and slow jet no 40, but I have 98 and 38. It ran fine with them earlier, but if I buy a kit should I replace them with the correct size?

Thank you

[riverfever]

I wouldn't buy a kit. They generally blow. You can find the gaskets on ebay and if you need jets get them through Jetsrus. For the o-rings...there should be measurements in the FAQ section. I bought an o-ring kit from Harbor Freight for many of the o-rings on the rack but I think for the main jets and the float valve seats I used the measurements and bought them from an online o-ring supplier.

[Adam77]

Here's a video of my pilot jet that doesn't screw in. Any suggestions?

[riverfever]

Yes. Helicoil. Or new carb body. 

[Adam77]

Have to sign in to view the video.

Whoops you're right. Fixed it.