1983 CB550SC... rebuild or custom....

[pvtace]

Soooo....  I just bought a 550 off a college girl through craigslist.   For being abused by someone who didn't really know too much about bikes, it is great shape, and worth the 400 bucks.   So far, from what I can tell,  I'm going to have to do very little to get the bike in tip-top shape....  I have never completely disassembled an entire bike... sooooo this might get interesting..   Also, I'm torn between restoring the bike to 1983 righteousness or customizing the bike for my own feel...what does everyone think?

List to do:
Fix electrical issue (headlight only works on high)
Replace clutch lever (bent)
Replace all rings / gaskets  (better safe than sorry, and there is a little leaking around the edges)
Change out the square headlight for a round one...it just looks too much like a weird crotch rocket to me with the square one
Replace or re-chrome mufflers (surface rust)
Remove rust (all of it appears to be surface rust only)
Paint job  (looks like the original was ruined by repeated fuel spillage)
Re-black engine pieces and frame pieces
possibly run all new lines if I find the old ones are toast...

Also, never had a nighthawk before this one, so the bike is new to me....
does anyone know the top out speed / rpm's for the 550, because it seems like this bike should go faster than 80mph... thanks
   

***Edit***
replace the seat covers
find a sissy bar w/ luggage rack
find / make a grab bar for when i don't need the luggage rack

[Munkey]

Nice find. I say restore it, but I'm kind of a purist.

And yeah, it should do way better than 80mph. During the early 80's the US government in their infinite wisdom and their attempt at saving our lives, decided to mandate that all motorcycles speedometers should only read 80mph. I guess they thought that people riding motorcyles would not go any faster than that since that's where the speedo stopped. Didn't work so well so the law kinda faded away after a short time. It did actually work on a few bikes. I had a Kawasaki that would twist the end off speedometer cable if you went over 80. The speedo needle would hit the peg and stop but the cable would just keep right on twisting. I went through 3 or 4 cables on that bike becasue occasionally I would forget.

[pvtace]

the speedo goes up to 120? i think.... but on the road it has been topping out around 80/85 mph, and rpm top out at 5.5k.... that's why i thought maybe something isn't right...

[pvtace]

Electric problem fixed.... there was this little piece of plastic holding the switch inside of the High/Low housing... it was not seated right...fixed that, and now the lights work great!   Next, change soft $25 saddlebags into $250 removable hardback saddlebags... project cost : $30...  I'll post pics when I'm through...  my thought is: removable, but the bike still looks nice after saddlebags are off.  I'm thinking chrome acorn nuts, some chrome washers, and some ingenuity.

[SmokinFast]

the speedo goes up to 120? i think.... but on the road it has been topping out around 80/85 mph, and rpm top out at 5.5k.... that's why i thought maybe something isn't right...

According to the specs its top speed is 116 MPH. Something is definitely wrong with your bike. Is it firing on all 4 cylinders? You can tell by spraying water mist on the pipes after the engine is thoroughly warmed up. The water should boil off instantly, not run down the pipes.

Also on these old bikes the carbs need to be cleaned if the bike has been sitting unused for a while. The gas turns to varnish and plugs the jets.

The other thing to watch out for is rust/debris from the gas tank getting into the carbs. I always add an inline fuel filter to the bikes I work on.

Brett

[pvtace]

cool, thanks for the tips

[pvtace]

Bike is firing on all 4. So I drained fuel tank last night, cleaned her out with alcohol to dry her out.  Pulled and cleaned the petcock off. I think the issue was fuel / debris.  I filled her up with high-quality fuel, and presto - 2nd-5th gear she got up to 8k rpm.  got up to 108mph on a short stretch.  Still got to clean the carbs though...    not looking forward to that... thanks for the info brett.

[detdrbuzzard]

clean carbs, drain crankcase breather,  replace air filter, and do a tuneup

[Munkey]

the speedo goes up to 120? i think.... but on the road it has been topping out around 80/85 mph, and rpm top out at 5.5k.... that's why i thought maybe something isn't right...

Sorry, I misunderstood what you were asking and couldn't remember exactly what years had the 80mph speedos.

I agree with the other posters, your bike is starving for fuel or air at higher rpms.

[gammer]

what does everyone think?

I am a purist too. Keep it original.
About the most I would do to it, is if you keep the square headlight, I might install a small cafe type of fairing...maybe. I'd have to think about it.

[Laminar]

Still got to clean the carbs though...    not looking forward to that... thanks for the info brett.

It's not bad.
http://nighthawk-forums.com/index.php/topic,4907.0

I've had mine up to an indicated 115. The speedo runs about 10% fast so it was probably closer to 105. And I waited until I had all new tires and brakes to go that fast. A blowout at that speed would be terrible. As far as RPMs go, I've hit 11,000 on mine. I haven't checked to see if there's a rev limiter.

[ndmeistr]

Mine will go well above 10K. I haven't opened the bike up full yet so I don't know how fast she goes but I've gone 95+ going up hill and have had plenty of throttle left.....Oh and...Keep it original IMO.

[pvtace]

ok...problem....
I went to start my bike after riding it to work.  There was no power to the bike.... i.e. i turn the key and no lights came on or anything.  So I tried to jump it from another bike...still no lights or power. I checked the fuses, including main and starter fuses, and traced the wiring... no corroded or loose wiring.  I didn't have a multi-meter, and I was extremely frustrated, so I left the bike at  work.  Any suggestions?
 

[geemann]

get a multi-meter and check your connections.

have the battery checked. is it original or did you replace it?

the 550's alt do not charge the battery when below 2500rpm, as a heads up.  electrically it sounds like you either have a bad connection or a drain somewhere if the lights did not even come on.

also, try running seafoam through the tank to help clean up the carbs etc, this should help diagnose problems further down the line.

my vote is to keep it as close to stock as you can, but customize away and really make it your bike!  I am all about making it your own and I feel the same way about the square headlight.

good luck!
~G

[Laminar]

When you tried to jump it, where did you connect the jumper leads?

Do you have the terrible stock "dogbone" strip main fuse?

I'd check your ignition key switch and your starter solenoid. Those seem to be the most common causes of these problems.

[pvtace]

I tried to jump off of the main wire from the positive terminal and neg  off the frame. got spark on frame when i moved it around. took the battery out to check for loose terminals/ corrosion, and tighted back down. The main fuse is the original.  I'm about to head out with my multi-meter, now that I have cooled off a bit... 

[pvtace]

I replaced the main fuse....the retarded college kid I bought the bike off of had connected the posts behind the fuse together with some copper wire... I think in an attempt to bypass the fuse???.... with a 30 amp ATM fuse housing.... replaced the battery, and I am getting no power volt or amp beyond the main fuse.....  I am confused

[chas550sc]

There is a connection inside the relay unit that ties the main fuse to the R/W and R wires coming from the plug. Check for power at the spades... corrosion in the plug,   the connections in the relay may need a rebuild

[Laminar]

Unplug the four-plug connector from the starter solenoid. With the solenoid connected to the battery and the fuse installed, do you see +12V on the posts that the red and red/white wires plug into?

[pvtace]

Thanks for everyone's posts!  The problem was the connector attached to the relay.  It was corroded badly.  Also, The fuses inside of the fuse box were all loose and not seated completely...  started right up, and actually ran better than before from a cold start.  Again, thanks everyone for the help!

***EDIT***
I also followed all of the cables, unseated and cleaned all of the other connections.  lets hope It cuts down on any silly issues down the road....
almost finished with the soft back to hardback saddlebag conversion.  I will post pics up of the process and hope it helps someone else out.  I am using the cutting-board method with a twist!

[Laminar]

Awesome. 

[geemann]

great to hear!  Looking forward to your conversion!

~G

[pvtace]

anyone know where i can pick up a cheap sissy bar / luggage rack.....or am I gonna have to make my own?

[ariwhiteboy]

You will most likely have to fab one out, our very own laminar might have a custom touring rack for sale though. 

[Laminar]