Topic: New here, reviving a rusty CB550 into a cafe racer, need tons of guidance

[geoluv]

Hello.  I am a vintage bicycle mechanic for a living but I decided to build a cafe racer.  I bought a 1974 CB550, can't remember if it's a "K" or "F", pretty sure it's a "F."  Boss maroon metallic.  It's pretty much all there.  I have the original air box, tool kit, rear light, etc.  It's in pretty rough shape, been sitting for possibly 30 years.  It was in a garage, but it must have been a pretty leaky garage because the rims are rusted on one side.  I checked the frame pretty closely before I took it home, frame seems ok, most of the rest of the bike has little rust on it at all.  The rims don't even really bother me because its just surface rust and in NJ where I'm going to register it there is no inspection.  I know how to build wheels so I can switch the rims any time. 

The bike needs to be re-wired, at some point it had a fairing on it but its been removed and the turn signals were incorrectly re-wired.  The engine moves, no idea if compression is good, all four plugs get good spark.   the front brake was completely seized, i need to rebuild the front lever and the caliper.  The tank has a minor amount of rust in it and the petcock valve doesn't close properly.  Carb 3 looks burned out, probably the reason the bike stopped being run. 

My end goal is a cafe racer but first I need to get it running.  I live in NYC and would like to find a place i can store it while I work on it like Vax Moto or Roll Up Brooklyn.  I'd like to find a place that has a mechanic that knows how to build cafe racers.  There use to be a place called "Wrench'n'Ride" in Bushwick where you could store your bike and they would teach you how to work on your bike but they are no longer there. 

If that type of place doesn't exist I'm ok with just giving it to a mechanic to get it running and then doing all the bolt-on stuff myself.  Who's a good Honda mechanic in NYC, Long Island, or Jersey?

[HondaMan]

I don't think the carb can 'burn out'? It probably just needs to be cleaned well. Actually, they probably all do after that long? If the engine still spins, it may just need some resealing/cleaning inside and then some miles on it: these engines tend to "self-heal" if they are just run enough. If you want racer-like performance, well, that's a different topic, though!

[carnivorous chicken]

IF it's a 74 it's a K -- F models didn't come out until 76 (some with 75 build dates, AFAIK).

Second Hondaman -- carbs don't "burn out."

Before you try to run it, do a 3000-mile tune up -- valve adjust, points clean (or replace) and gap, new plugs (or clean the old ones), oil change, timing, etc. You might want to put a few drops of oil in each cylinder before you fire it as well. And as Hondaman stated, you should probably pull the carbs and make sure they're clean with correct float heights. You've got pods on there, so the previous owner may have rejetted for those; if not, you might have to do some work to get the jetting right.

I worked on a few bikes in NYC last fall. There are a couple places where you can store you bike and wrench on it as well, can't remember any of the names, but poke around and you'll likely find one. The folks at Moto Grrl in Greenpoint are good people as well and might be able to point you in the right direction.

Doing work like this yourself will take some time but save you a ton of money. Other folks here prefer to take it to a mechanic, but it's tough to find a good one who works on vintage bikes. Either way, good luck.

[calj737]

Absolutely a bike to rebuild yourself if you have the means (some time, patience, and a few decent tools). Work space is probably the toughest challenge for folks in your area. There's nothing you mentioned that is more than a few weekends to refurbish, even the carbs. The manuals for your bike are available on this site, and so are the wiring diagrams.

Your bike is a very simple wire plan, so correcting it won't take much time. Carbs you can remove and send to a member here, Harisuluv, who will rebuild them properly and return them to you for installation in better than new condition.

If you do seek a cafe style, most of the original parts on your bike are sellable to help fund the build/restyle project. And there's heaps of sources for new or factory parts to aide in the build.

Cheers!

[evanphi]

Welcome to the forum. Your two first replies are from two of the most knowledgeable people on this forum. Follow their advice.

You can do this work yourself... it mostly involves cleaning with gentle solvents and small brushes. Wiring is easy, too. Everything is colour coded, and you can find your wiring diagram on this site.

Have fun! 

[geoluv]

Thank you all for the advice and warm welcome.  I bought the bike on eBay from a seller in western PA for $1,380 USD.    I drove through 12 hours of fog to get it.  He had already rebuilt the carb (notice the new float in the picture), but claimed he stopped because when he was rebuilding the carb he lost one of the clips but had found the clip before the auction ended.  I think what really happened is he rebuilt the carb, discovered carb 3 was leaking because carb body 3 is so corroded that it doesn't form a good seal around the o-ring on the main jet (see same picture above).  What could have caused this?  This doesn't bother me that much because a new carb body #3 is only $50.  He said when he got the bike the engine didn't move but he put a few drops of oil in the cylinders then let it soak in and then the pistons moved.  Like i said before I need to rebuild the front brake caliper and lever too.  I forgot to mention it has very low miles for it's age, I think only 8,000 miles.  The tank has no dents and the paint is still good.

I've since learned that what I want to build is called a brat cafe, not a cafe racer.  Clip-on bars, fat tires, minimal rear lights, and a custom flat seat that's a little thicker than you're average brat seat; somewhere between a brat seat and the stock seat.  I'm going to keep the side covers on, I want to eventually run pods because I want to build a custom storage box under the seat. 

What mods would you guys do to make a tough brat cafe to bang around NYC with and do a few 3 hour upstate runs with?  I want to get ideas from you guys before I start my build thread.  Rev limiter?  Wire mesh over the headlight?  big bore kit?   

I have the work space (I have a place to store and work on my bike for free that is one block from the official NYC Honda motorcycle dealership in LIC) but what I don't have a lot of is time.  When I bought the bike I had more time planned out to work on it but now I don't.  Ideally I would drop my motor and carb with someone, re-wire the bike and fix the front brake myself, install the new bars and seat, then by the time i'm done with that my motor should be done.

[calj737]

Clip-ons and a flat seat are counter-productive to each other. Flat seats diminish the friction and support for your body weight, the clip-ons extend your reach and force the full weight onto your wrists. Clip-ons are generally best installed in conjunction with a rear set configuration to move your ankles back too.

Anything obstructing the already limited pool of light from your headlight is a poor idea, but that's your call. "Fat" tires like the ones pictured diminish handling and braking. Better to use quality tires (Bridgestones, Dunlops, Avons) and improve your bike's handling and braking than chase an "aesthetic".

If the motor is as low mileage as you think, dropping it off to be rebuilt seems wasteful. Perhaps have the bike undergo a full 3K Service, including have the carbs rebuilt by a known carb professional would be all you require. I dislike dropping my bike to "shops" to have carb work done. Often they swap the stock brass and components with cheap aftermarket products because they don't know better, and actually make things worse, not better. And you redo their work later. It doesn't take much time to service that engine. And you will be far better off knowing it and doing it than paying someone to muck with it.

[geoluv]

I wouldn't go as extreme on the fatness of the tires in that picture, and also not nearly as thin on the seat padding either.  I'm very short so naturally I'm already going to be very far forward with the clip ons, I'll basically just be hugging the tank.  My short torso will put the pegs more back relative to my seating position from my torso being drug forward by the clip ons.  I kinda need the lower seat and lower bars simply from being "inseam challenged".   I'm probably going to end up lowering the bike a smudge too.  The aggressive position is actually something I want, I'm use to the aggressive geometry of my bicycles where the saddle is actualy higher than the bars.  My body is use to this position. 

I'm kinda just leaning twords doing the carb myself unless there is a guy within 1 hours drive of New York City I can dump it with.  I don't want to ship it.  Does anyone have a link to a good guide to rebuilding the 022a carb?  I have the service manual but I always like a nice full picture guide or YouTube video to compare it to, but I don't want to watch a YouTube video of a guy who doesn't know what he's doing.

[calj737]

Fair enough, but you still need to move the pegs rearwards to have proper control. Unlike a bicycle where your feet need to be beneath your hips to peddle, a motorcycle's pegs are for control and operation. So ergonomics matter.

[geoluv]

I should also say that modification of the frame or anything else is ok with me.  My brother is a union welder, I have access to CNC machines and powdercoaters.  I have the means to build this thing exactly how I want it, just little time.

[seanbarney41]

Get a service manual, learn how to service your bike, learn how to ride (bicycle experience won't get you very far), get some experience riding a STOCK vintage bike.  All this should take about 3 years.  By then, the changes you want to make to your bike will be pretty easy, but you will have the knowledge and experience to realize that your planned changes actually will make that bike SUCK.

[carnivorous chicken]

Others have offered good advice so far. Big tires, even tires that are simply bigger than recommended but will fit on the rims, reduce the handling capability of your bike. They're a bad idea, unless you want to go slow around the corners. I'm not a fan of the whole "brat" thing, and "brat café" is another amalgamation that someone simply made up. When people build "brat" seats, they frequently just put a flat seat pan on the frame rails (usually after chopping off the support between them). On the CB550, this support sticks up a little, so when you put a flat seat on it the rear tire rubs on the underside of the seat as the shocks compress (exacerbated by those big tires). This is very dangerous. And of course you lose the stiffness that the support provided for the rear end of the bike. The advice you've received about clip-ons is correct too -- ergonomically, you're going to need rear sets. Running the smallest possible tail light also reduces your visibility to drivers behind you, something to think about.

These changes aren't just a matter of aesthetics, they are a matter of function (and safety). Ultimately, it's your bike, but seabarney's advice is spot on -- run a stock bike for a while so you know what it feels like, then make some decisions. If you do all the things you're proposing, you may be permanently altering your bike in a way that you'll regret when you realize just how badly it performs. Again, it's your bike, do what you want, but while some people may think bikes like that 750 look cool, anyone who knows anything about bikes realizes what a shame it is to do that to such a cool bike.

Once you get a 3k mile tune up done, run your bike for a while. Your compression might come up a little. Although some of your numbers aren't even and on the low side, I think your bike will run ok, at least until it gets worse (unless it gets better!).