Topic: CB550 - The 1976 brat project (wiring with a M unit)

[hashvm]

Hi All ..

This is my first post here on the forum. I've been reading and gaining a lot!
So, I took my love for cars to the next level: motorcycles! I fall in love with the old Hondas style. So here's the thread of my build to share my experience and get support.

So the story of this one:
This is my first build ever. I have no prior experience with motorcycles. I found this 1976 Honda CB550K for less than $500. The guy who sold it to me had bought it to take the exhausts from it for his other bike then decided not to. It wasn't running when I first got it.

[hashvm]

Since the bike wasn't really running, I started by getting a new battery to try to fire it.
It DID! However, it didn't really run for more than a couple seconds, so I knew that i Had to look into the fuel system.

I got Kits for the carbs and took a look into the tank .. and man it was Nasty!
So I tried to clan the tank .. shock it a little bit .. and ..

Next I did work on the carbs and rebuild them.

Then I got some K&N pods filters and install them too.

[hashvm]

Then I fired it again!

[mpgholston]

Good luck on the build. Going through a restore myself. When you put your hands on those bars does it feel like your reading the newspaper?

[hashvm]

Welcome. The carb rebuild kits should only provide some gaskets and o-rings. The stock brass is much better than aftermarket. If you have swapped the stock brass out, find it and keep it, despite its condition because it usually will clean up.

Now that you know it runs, time for a complete service of the engine. Here's a section of this forum with complete manuals, service data, wiring diagrams for your use http://manuals.sohc4.net/cb550/

The idle sounds a tad low in the video, so a good tune up and adjustment of that will surely bring the bike to good life. Definitely need to ditch those bars and seat 

Hi Cal,
I was actually looking for the original kits online. The bike came in with an aftermarket one when I got it. I looked into JetsRUs but I got confused since they don't list the carbs by names (087A).

For the idle, I figured that my fuel air mixture needs more gas parts, especially after I added the pods. It runs and gets to 2000 or 3000 rpm instantaneously. I did clean the tank and as we speak the tank is in Metal Rescue.

[hashvm]

Good luck on the build. Going through a restore myself. When you put your hands on those bars does it feel like your reading the newspaper?

Hi mpgholaton, thanks!
Oh man, these bars are coming down as soon as I begin working on the frame. 

[SOHC4 Cafe Racer Fan]

Once you have the tank cleaned, you might want to take it to a radiator shop for a pressure test (for leaks).  Depending on the amount of rust, you may need to address some pin hole leaks. 

[hashvm]

Cal, I'll look into that. I hope I still have a tank too 

Cafe Racer Fan, thanks for the advice .. I'll check it out.

[hashvm]

So this weekend I started taking everything apart

Initially, I was planning on getting the rear wheel out to de-rust it, but when I got it out I just couldn't resist the idea of tearing it apart then do every little task by itself.

I got everything out but the engine, which I'm going to do next.

I discovered a fearful rust area on the back of the bike that I have no idea how to deal with. I'll try to sand what ever I can from it and work my way from there.

The good news is I found a clean swing arm in the box the PO gave me. 

Here's how she stands now ..

[hashvm]

Here are the rest of the pictures ..

[hashvm]

So Finally I was able to start tearing the 550 slowly apart .. Here's how she looked a couple of days ago



Now that it's completely torn apart .. It's time for some cleaning ..



Surface rust never hurt .. right?



However when I finished this rim I ended up with this black spot here .. it feels like it's just a tip deeper that the rest of the chrome




Now should I just use filler and sand it down since I'm gonna paint it anyway?

And when I was looking for spokes for the rear wheel, I only found the kit for the 77-78 k models .. does anybody know if it's the same ones for 76?

Next, is gonna be some hoop work and powder coating  next week .. 

Hashem

[hashvm]

and while I'm on it .. do you guys know if I can mount the 77 tank on the 76 with no mods?

[hashvm]

Here we go

It's been a while since I last posted on this topic

The CB550 came a long way since then, here are some of the mods:
- cleaned the engine (no rebuild tho)
- Powder coated the frame and wheels
- added tappered bearing to the TT and bronze inserts to the swing arm
- rebuild the carbs + added K&N pods
- new dayna ignition system
- clip ons and new switches
- New headlight and taillight

Some of the stuff I need to add to finalize the build:
- M unit for a completely new wiring harness (doing that at the moment)
- New Progrissive shocks with HD springs.
- A new gauge

Here she is after the rebuild just after the first start up beside my 80 CB750F


And here's one of the best moment of my life seeing my first rebuild firing after I put it back together:

Still I have couple of stuff to get it on the road ..

[hashvm]

here she is now during the wiring process (excuse me for the messy garage):




I'm thinking about making a mount for my Shorai battery in here, to mount on the back of the engine, I just don't know how


The suspentions, the gauge, and my machined footpegs (one of the perks of being a student in the university with machine shop access  )

[hashvm]

One of the things I was looking at is to find an emblem for the tank

this tank is off a F model (1976 I think) .. and I spent a good amount of time looking for a replacement with no result

any idea where I can find a set?

also I was thinking about painting the tank with a gloss silver just to get closer to its bare metallic look, I kinda like it

Hashem

[SOHC4 Cafe Racer Fan]

I doubt you will want to literally mount the battery off the rear crankcase.  There will be a significant amount of heat transfer to the mount and your battery, and it will likely cause a premature failure or worse.

[Moosey]

Boy that looks much better...esp since those handlebars are gone!

[hashvm]

Are you planning on making your own rear set, or adapting the pegs you've made onto someone else's set? Your pegs look a little long, but perhaps its the scale of the picture.

Cal,

The plan is to use these with the original pegs mounts as in the original setup

It's gonna be a rider/passenger bike so it's easier to work off the original parts

[hashvm]

I doubt you will want to literally mount the battery off the rear crankcase.  There will be a significant amount of heat transfer to the mount and your battery, and it will likely cause a premature failure or worse.

Oh shoot I totally forgot about heat, any other mounting points for the battery you think?

[hashvm]

Boy that looks much better...esp since those handlebars are gone!

Believe me it was task #1 to get those handlebars off 

[hashvm]

I've been trying to figure out this M unit wiring thing for a while now 



First, what is the G circle beside the reg?

Also do they mean the points plate with the "ignition box"?

I started connecting the M button to the left controls and working on the right controls now

I decided to get everything in place first then connect everything. so here's what I have so far + 1 in line 15Amp for the main fuse



Am I missing anything?

the Aluminum plate will be remade and the parts attached to it will face downward, that way I can attach the seat to it.

I was also wondering if I should connect the start button straight to the ignition solenoid since it's using the same colors?

I really wanna get this thing fully running so any help would be appreciated

Hashem

[hashvm]

That G is the stator/alternator (They used G to represent "Generator")

The electric START button on your handlebars runs into the left side START button. From right side START to Solenoid. The thin GR/R wire from your solenoid you will need to run to GROUND now.

What handlebar switches are you using? If you provide me details on handlebars, gauges, key switch etc. I can whip you up a color diagram with the M-Unit to provide you a clearer picture.

Cal, thanks for the reply

I'm using reproduction OEM style controls like this one:
http://4into1.com/reproduction-throttle-switch-assembly-35300-341-671-honda-cb550k-cb750k/

I'll also be running a 2.5" gauge like this one:
http://www.dimecitycycles.com/2-5-inch-black-mini-kph-speedometer-with-black-face-indicator-lights-and-tripometer.html

for the key switch I'm just using the old one it came with (looks like OEM)
Thanks again for the help

[hashvm]

Any tach?

nope, just a speedo

[hashvm]

Also for the wire from the solenoid to the starter, what gauge does it have to be? I assume it carry a lot of current.

[hashvm]

So I made this wiring diagram, does it look okay?



The only thing I'm missing is how to wire the single Reg/Rec unit. Also right by the points where I have the question marks, where is that supposed to go?

sorry I know it's a lot of questions

Thanks again for help

H