Author Topic: First Build: CB550K0 Back From the Dead!!! (Read 8134 times)

geoluv · « **on:** June 18, 2016, 07:25:02 AM »

I've been obsessing over 70's Honda SOHC motorcycles for a few years and finally pulled the trigger. I live in Brooklyn so finding these bikes in good condition for cheap is not very easy. I watched CL, eBay, and all the locals all winter and bought a '74 Boss Maroon Metallic CB550K0 for $1,380 on eBay. I had to drive to western PA to get it. It hadn't run in possibly 30 years, was garage stored but the rims are pretty rusty. Frame seemed good to go, I checked it pretty good before I took it home. The rest of the bike doesn't really have too much rust, just a moderate amount of gunk caked onto it.

I did as much of the 3000 mile tune up as I could, minus the timing because I couldn't find my timing light. I rebuilt the carb and scrubbed all the gunk off everything but i didn't have anything to soak it in so i think some of the little tubes in the carb bodies are still clogged. I jumped the battery and started it with the starter. It actually started and idled for a moment or two. I didn't want to push it so I only let it idle for like 30 seconds. I haven't set idle or anything, I just held the throttle. I just wanted to see if the bike would even fire before I go any further and spend more time/money on this thing. One or more of the carbs were leaking badly, which was disconcerting because I thought I cleaned the carbs pretty good and was pretty good at making sure all the moving parts functioned properly but I had no carb cleaner. Didn't catch which one was leaking, didn't have a lot of time to work on it. When I revved a bit it it would die. It's not getting enough gas me thinks.

I no longer own a bike that "doesn't run", now I just own a bike that needs "sh#t loads of work, BUT RUNS!!" I'm going to rebuild the carb correctly with carb cleaner, blow out all the tubes in the bodies, polish the bowls and lifter caps, maybe paint the bodies black, paint the heads of the bolts black, then re-install. I will get a timing light and time it correctly. Then re-try.

Any advice for me thus far?

calj737 · « **Reply #1 on:** June 18, 2016, 08:05:20 AM »

Do a complete and proper job disassembling your carbs and clean every jet and tube and orifice. Else you will be repeating this step over and over.

You can also verify the fuel level in each of the carbs via Clear Tube method to be certain things are right. And inspect the interior of the gas tank. It must be rust free or it will transfer funk to your newly cleaned carbs.

geoluv · « **Reply #2 on:** June 18, 2016, 08:11:23 AM »

^ i'm just running inline filters for now until i know this bike can be made road worthy. Even after I seal the tank, if I get that far, I'm still going to run the filters.

SOHC4 Cafe Racer Fan · « **Reply #3 on:** June 18, 2016, 03:49:57 PM »

Welcome to the Forum, geoluv.

Cal's right about your carburetors. They will need a thorough rebuild and clean. Even an unltrasonic clean will not get to corrosion on the jets. Good on you for doing as much as the 3K service as you could, though!

Bankerdanny · « **Reply #4 on:** June 19, 2016, 06:56:03 AM »

The jets can be very difficult to get clean. I keep some guitar e-string in my tool box to help unplug the jets so the carb cleaner can get through. You can usually get some leftover string from your local shop for free.

Tews19 · « **Reply #5 on:** June 19, 2016, 05:47:55 PM »

Buy a gallon of "the Gunk" for your carbs. Works great. Any pics?

geoluv · « **Reply #6 on:** June 24, 2016, 09:34:51 PM »

pics coming soon!

I'm about to fire it up and ride it around for the first time, just gotta fix one turn signal and do the carbs.

a few questions though: I need to lower the bike, the fork tubes I can just slide up but what cheap rear shocks should I be looking at on eBay that have adjustable hight? i would prefer ones with true adjustable hight not just spring tension.

also what jets should I be running if I have pods and 4 into 2 exhaust? I'm pretty sure the carbs are still stock jetted.

Also I need new tires so i might as well get new rims to match while I'm at it. What is a good "any price" rim and what's a good cheap rim option for this bike? I also want to go a little wider than the stock tires to soak up the NYC potholes.

Tews19 · « **Reply #7 on:** June 24, 2016, 09:50:38 PM »

Don't waste your money of new rims. Steel wool triple 0 will help out immensely!

Also why do you want to lower a 550 more? I'm short, 5'9 and the 550 is perfect height imo. Also do you have the stock airbox? Pods are a PITA.....

geoluv · « **Reply #8 on:** June 24, 2016, 11:08:30 PM »

the stock rims are rusted to the point where they wouldn't pass inspection in some states. Not my state but whatever. I can build wheels myself so changing rims is no biggie. or i can just plastidip them black. Honestly I want to spend money on wider, lighter rims. i have the stock airbox but i like the ease of working on the bike with pods, and i want to run pods eventually so i might as well just tune it correctly now.

with pods you jet it, adjust needle, sync it, adjust mixture and thats it? am i forgetting anything?

my bike has 4 into 2 exhaust, I'm not sure if that was stock for that year, I'm pretty sure it came with 4 into 4, and i think the carb has the stock jetting so ill have to order new jets anyway. I might as well order the jets for pods not the stock airbox. I'm trying to spend as little money as possible and sell what I don't need. I figured these bikes are pretty thoroughly gone over so people would know what jetting is best for my setup but if you think it'll be easier to get it going with the stock airbox I'll put it back on and order the correct jets for the stock airbox with 4 into 2 exhaust.

Also I need the bike as low and light as possible because I am about 5'6".

calj737 · « **Reply #9 on:** June 25, 2016, 03:42:28 AM »

Lowering your bike can create interference issues of the rear tire to the inner fender/seat hoop, so proceed cautiously.

Cheap and Adjustable shocks are oxymorons. Only good quality shocks can be adjusted, and that means +$600.

To find a wider rim, you don't have a lot of great options unless you buy some aluminum Excel or Sun rims, and then 2.15" for the front and maybe as much as 3.5" for the rear is about all you can safely stuff into them. Any wider on the rear and you'll be considering offset sprockets. And there's not a spoked wheel/tire out there that can endure the potholes in NYC without taking some damage, so get used to truing and replacing your rims.

Pods can be tuned but will not ever run "as well as" a stock airbox. As to what jets and carb settings you should run, it differs with every setup. Exhaust, location, motor specs, riding style, etc are all factors that effect the final tune.

Quote from: geoluv on June 24, 2016, 11:08:30 PM

with pods you jet it, adjust needle, sync it, adjust mixture and thats it? am i forgetting anything?

Yes, you are forgetting, plug chops, re-tuning, more plug chops, more tuning, and more plug chops and needle adjustments. Throw in a few float level checks and adjustments, and another tweak or two with a final plug chop. Should only take about 2-3 weeks to get them decent and close.

geoluv · « **Reply #10 on:** June 25, 2016, 06:24:45 AM »

Rear tire clearance is something I'm just going to have to deal with. Having to run stiffer suspension with little travel is another reason i need a fat tire; to make up for the minimal amount of travel I'm going to be left with. If i keep the bike I'll buy fancy shocks but for now I just want to get it running and set up so I can actually ride it around for a week or two to see if I want too keep it. I love this bike but its 430lb weight is a little unwieldy for my small frame in a city (how much do these things weigh when stripped down?) I should have gotten a 450t or 360 but I wanted to be able to achieve highway speeds for long rides. What I REALLY should have gotten is a cbr600 or early 90's ninja but I feel like my degenerate street bike hooligan days are behind me.

calj737 · « **Reply #11 on:** June 25, 2016, 07:20:39 AM »

You could swap front and rear rims sizes too. Drop to an 18/17 combo and buy yourself a bit more reduction in height. Fatter tires don't yield more resilience, taller or stiffer sidewalls do. But that counteracts your goal of a height drop.

geoluv · « **Reply #12 on:** June 25, 2016, 12:43:30 PM »

If I got smaller with the rims but get tires that achieve the same diameter as the stock tires that would add cushin to the ride without sacrificing top speed.

calj737 · « **Reply #13 on:** June 25, 2016, 02:59:22 PM »

You'll get close on the aspect ratio giving you back a standard tire diameter, but it won't be exactly the same. Nonetheless, it will give you some more cushion. A 120/90-18 front and a 130/90-17 rear would be a good combo.

JetgreenK1 · « **Reply #14 on:** June 25, 2016, 07:59:58 PM »

Geoluv,

Congrats on the bike! Glad you could snag something for a decent price. I just did my CB500 K0 carbs. I also have about 5 empty gallon jugs of simple green. The stuff works wonders on getting into small spaces. Helps even more if you have a heating ultrasonic parts cleaner. But I had been using small pipe cleaners for the small crevices and jets. I'll need to try guitar strings. Send us pictures!

geoluv · « **Reply #15 on:** July 02, 2016, 01:14:59 AM »

So I went back out to the house in New Jersey where my bike is. I took apart the carbs, soaked them in a 1/1 solution of that crappy walmart degreaser and water. Scrubbed everything an put them back together, and as I was blowing out all the holes I cracked the overflow tube on one of the float bowls. Put a crack right down the middle of the brass tube. I guess it was just brittle and couldn't take the pressure, my compressor was set pretty high though. I immediately ordered a new float bowl on eBay and went about pulling a shady tree mechanic move: I used a wire tie with its plastic removed to tie the cracked tube back together. I figured it would be fine just for getting the bike running for now. So I button it up and start it with the starter and she purrs like a kitten. I pump up the tires and take her for a spin sans front brake because I haven't rebuilt it yet. The exhaust spat a little (I think white) smoke for about 20 min, and the outside of the exhaust smoked like crazy too from 30 years of oil and grime and rust being cooked off. After a bit both the outside and the inside of the exhaust stopped smoking. After that I drove it around my neighborhood for the first time. It was sublime. I've never worked on motorcycles before, or even carburetors for that matter. My dad didn't believe I was going to get this thing running in what was effectively two days of work.

Now for some questions for the experts:

1. My shady tree mechanic move worked, that bowl didn't leak. Buuuuuuut carb three had a little trickle. It was a very minor trickle. I'm thinking it could be one of two things: On one of my float bowls, I forget which carb I bolted it to, but the overflow tube was ever so slightly bent. Im thinking a little leak could have formed where the tube is pressed into the bowl. Possibility two is that there is something that is not exactly the same about carb number 3, because I replaced carb body number 3 wth a carb body from a '73, cb500. People on the internet claim they are the same, just marked different because of the jetting, but I noticed the hole opposite the slow jet hole is not threaded on the cb500 carb, and it is threaded on the cb550 carb. It makes me wonder if they are not truly identical. And of course option three is I did not set the float right because I was using a paper Ikea measuring tape.

2. Some PO had a fearing installed and then removed. They did a hack job of the wiring. As far as I can see all the electronics on the bike work correctly aside from the right turn signal staying on all the time when the bike is on when none of the other lights do. It starts blinking if I use the right turn signal, beeps at me and everything. But when I turn off the turn signal it goes back to being on continuously until I turn off the bike. Any suggestions on what I should look at first to fix this?

3. The front brake lever is seized, and the lines were contaminated and filed with crystals. I don't know of a way to clean the inside of the stock front brake lines so I'm going to rebuild the caliper for good measure and get a steel braided line and a new lever. Is this lever set good for my bike: http://www.ebay.com/itm/7-8-MOTORCYCLE-Brake-Hydraulic-Cylinder-Master-CABLE-Clutch-Lever-US-NEW-/371670192854?hash=item56894512d6:g:PcYAAOSwBahU~UWt&vxp=mtr?
Also if I wanted to not be a total cheapskate and actually buy some nice levers, does anyone have a recommendation on a set of levers that would match the "look" of 70's bike but are "dog leg" style? I have size medium hands but I like to grip my levers with my second joint on my finger not my first. White knuckle NYC riding and all....

4. What are some good bars that have the same bends as the stock ones but are about an inch shorter and maybe 1-2 degree more backsweep?

5. Lowjack? I know too many dudes who have gotten bikes crappier than this one stolen in the city. I have a good place to store it at night but I'm worried about it being jacked in the middle of the day when I'm out and about.

6. I know everyone said put the stock airbox back on, well I discovered that my bike only came with about 80% of the original airbox. I just left the pods on for now but I'm going to get the rest of the airbox and put it back on. Thing is, I think my bike might be jetted correctly because I should jet up one size for the pods but down a size because I have 4 into 2 exhaust? As opposed to the stock 4 into 4?

I' d like to thank everyone on this site for all the info i needed to get my bike running. I'd also like to thank my dad's impact gun, without which I would not have been able to remove the oil filter housing bolt or the two big bolts in my brake caliper.

and as promised, picture:

calj737 · « **Reply #16 on:** July 02, 2016, 03:43:18 AM »

Jetting for pods really needs to go up. With a 4:1 exhaust, jetting needs to go up, not down.
That brake line is fine. Difficult to find dogleg levers for our bikes unless you change the entire lever/perch.
It may be the PO wired the R indicator to a "running light" condition and the L is not. You'll have to compare the wires on both to see if they differ. It could also be the changed the actual bulb and one is 2 wire, the other is 1 wire.
Low jack might help. Good luck, its NYC. $:-\$
For a float level tool, take an old credit card or MVP card in plastic, and cut it exactly to the proper measurement. Slips right into your wallet and won't flex on you.

Buy fresh tires! You may also really need to repair/rebuild/replace your master cylinder on the RH bar. www.davidsilverspares.com sells a repo unit for $40 that is far easier to use than successfully rebuilding yours.

Norman Hyde M bars are popular choices for replacement bars.

b52bombardier1 · « **Reply #17 on:** July 02, 2016, 06:51:17 AM »

I've seen those brass overflow tubes that stick up from the bottom of the float bowl crack due to water freezing in them. Obviously, that float bowl will now seep fuel out that overflow tube regardless of what the float height is or the health of the float valve. The cracked brass tube could possibly be repaired with some hobby brass tubing slipped over it and then JB Weld'ed in place. But if you can get a new float bowl then do that.

Rick

geoluv · « **Reply #18 on:** July 03, 2016, 07:23:03 PM »

So iI went and made a mess of things today, I went to fix the front right turn signal, and somehow I fried something in my bike.

I pulled the headlight off and traced back the two wires, I found the light only stayed on when the lights were turned on. So I pulled both cables out from where they were connected and I turned on the right turn signal and found the correct connection so now it works and doesn't stay on constantly. Then I bench synced the carbs, I had forgotten to do that, good thing I did because one slider was off a bit. I got all excited to go ride my bike now that it would run even better from the carb sync. I go to start the bike, I try starting it for a bit with the electric starter but it doesn't fire. No spark. I realize I have the kill switch set to off, turn it to on, but the bike still seems like it has no spark. I go get jumper cables and connect them, but when I do I notice it doesn't spark at all when I rub the positive jumper clamp against the positive battery terminal. Thats bad, it means my starter switch or regulator got fried right? Good thing they are both relatively cheap. One week ago this bike fired up perfectly every time. Then all of a sudden the bike dies completely, no power going through it at all. I pull apart the ignition switch and see the total mess the PO made of the connectors. The black cable had broken off from its connector, leaving just the nub of solder the wire previously came out of. I don't have my solder with me so I just use electrical tape to tape it together and then the bike lights up again. Everything about the bike's electrical system seems to work fine aside from the spark plugs not sparking. At one point when I am laying on the starter motor, trying to diagnose the no spark problem, the starter motor keeps revving after I release the button, I have to undo the positive battery cable to make it stop. I wait a bit and reconnect and the starter motor seems to operate normally again. .

Did I fry the battery/regulator/starter switch when I was fiddling with the wires in the headlight? I was pretty careful but who knows maybe i touched two things together that shouldn't have touched? Did I burn up the starter switch from using the starter for too long when i was trying to fire it? I didn't use it too much I don't think but who knows. At one point when I went to unlock my seat the key scraped my positive jumper clamp and arched for a second but I don't think it was long enough to short anything.

I was soooooo close to riding this thing around, now it won't spark. Both ignition coils send no spark.

This would be a good time to upgrade all the electric bits in the bike, wouldn't it? I noticed most of this stuff isn't very expensive, the regulator is 100$ but everything else is cheap. I want to keep my ignition switch though because I like how I have all the original keys that came with the bike and they are keyed for the seat too.

calj737 · « **Reply #19 on:** July 04, 2016, 03:47:58 AM »

It sounds more like the RH START button wiring (Yellow/Red) is wonky. That, and the KILL switch wiring (BLK/WHT) that leads to the coils.

The Y/R trips the solenoid, so it may be "stuck" in a depressed mode, constantly trying to turn the starter.
The BLK/WHT feeds 12v to the coils, you can verify you have power at the coils by using a meter and testing the double bullet connector (1 wire from bars, 2 individual wires to coils) that carries the power out of the KILL/RUN to the coils, under the tank, behind the headlight.

geoluv · « **Reply #20 on:** July 04, 2016, 11:05:26 AM »

Decided to spend my 4th working on this moto, because what's more patriotic than working on a Japanese motorcycle on the 4th of July?

So I went about tracing back these faults. I found my soldering kit and reconnected the black wire to its nub on the ignition switch. Then I took apart the kill switch and started tracing it back. You were right Cal, the bw/bw connection in the headlight from the kill switch had come unsnapped, possibly from when I was fiddling with the turn signals. Connected it and got spark, the bike fired right up.

I noticed the bike has what I would say is not a lot of power and is very loud, haha, is this normal? I feel like my 150cc Vespa has almost as much balls off the line, but then again they are specifically geared for 0-30 mph acceleration.

So now I have a running CB550. What's next? I definitely need new tires/tubes and I want to install the needle bearing headset kit. I'm going to leave the stock rims on for now, but when I switch tires I'm going to plastidip them black. I know I need new tires badly but I don't want to relace new rims on just yet. I really want fatter tires because nice round fat tires have more predictable, smoother handling in sharp right angle turns in the city. With fat tires you can slowly roll your weight over whereas with skinnier ones when you take a lower speed turn you're either standing up on the tires or you're falling over. What tires would be good for the city and are cheap and have a vintage tread pattern? What tires would be good once I get fatter rims? What needle bearing kit should I get? I have a headset press.

I still want to rebuild the stock MC lever, but the piston is stuck in there really badly. If I put a punch in the line hole and just start hammering am I going to mess anything up, or even get the piston out?

Once again you guys have been amazing, everyone in my parent's neighborhood is ripping around on their motorized toys today and I got to join in the fun. After yesterday I was bummed thinking I wouldn't get to. Everyone LOVES the bike.

calj737 · « **Reply #21 on:** July 04, 2016, 04:31:39 PM »

For tires, forget "vintage" tread patterns, and focus on quality "stickiness". Shinkos are popular with Urbanites, Bridgestone BT-45s are well regarded, Avons, Dunlops, Metzlers, etc... NO FIRESTONES!

geoluv · « **Reply #22 on:** July 04, 2016, 07:49:59 PM »

^Ha, you could tell I was thinking Firestones just from the "vintage tread pattern" huh? In all honesty why do some people hate them so much, but I see them on so many cafe builds? They look sooooooo cool.

After i typed up the last post I went back and looked at the wheels real close and I feel that the spokes are too far rusted. on the back wheel it is to the point where it concerns me, so I guess I might relace the wheels now so I need rim suggestions. Basically how fat can I go in the stock frame/fork?

Also I forgot to ask this two days ago when I rebuild my carbs, but what the heck is this washer and where does it go?

When i rebuilt the slide lifter assembly it was left over, so it obviously does there, but it was the only single washer like this so I don't know which slider it goes to. All the other washers there were 4x of. The bike doesn't seem like it needs it but I definitely want to put it back on.

geoluv · « **Reply #23 on:** July 04, 2016, 07:52:05 PM »

My all time favorite urban tire for motos are the Michelin CityGrip. Not sure if them make them in my bike's size.

calj737 · « **Reply #24 on:** July 04, 2016, 08:36:07 PM »

A 140-18 rear will fit in your stock arm Witt requiring offset sprockets. For the front, I'd stick to a 110-19 maximum.

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Author Topic: First Build: CB550K0 Back From the Dead!!! (Read 8134 times)