Author Topic: CB550 - The 1976 brat project (wiring with a M unit) (Read 10562 times)

hashvm · « **on:** July 10, 2015, 08:18:51 PM »

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 · « **Reply #1 on:** July 10, 2015, 08:41:11 PM »

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 · « **Reply #2 on:** July 10, 2015, 08:42:25 PM »

Then I fired it again!

calj737 · « **Reply #3 on:** July 11, 2015, 04:31:55 AM »

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

mpgholston · « **Reply #4 on:** July 11, 2015, 04:47:18 AM »

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 · « **Reply #5 on:** July 11, 2015, 09:16:15 PM »

Quote from: calj737 on July 11, 2015, 04:31:55 AM

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 · « **Reply #6 on:** July 11, 2015, 09:19:22 PM »

Quote from: mpgholston on July 11, 2015, 04:47:18 AM

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.

calj737 · « **Reply #7 on:** July 12, 2015, 04:43:48 AM »

Hash - the super high idle is more likely a vacuum leak and improper tuned carbs than a result of just adding pods. Pods tend to effect the main jet, not idle jet.

It will be interesting to see if there's enough metal left in the tank to hold gas

SOHC4 Cafe Racer Fan · « **Reply #8 on:** July 12, 2015, 09:16:12 AM »

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 · « **Reply #9 on:** July 12, 2015, 02:03:35 PM »

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 · « **Reply #10 on:** August 07, 2015, 02:21:53 PM »

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 · « **Reply #11 on:** August 07, 2015, 02:24:53 PM »

Here are the rest of the pictures ..

calj737 · « **Reply #12 on:** August 07, 2015, 02:43:57 PM »

Degrease the frame and use a rust converter on that area. Afterwards, you can better determine whether the rust did sufficient structural damage to warrant repair or was superficial.

hashvm · « **Reply #13 on:** August 20, 2015, 10:41:48 PM »

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 · « **Reply #14 on:** August 21, 2015, 12:45:15 PM »

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

hashvm · « **Reply #15 on:** September 30, 2016, 10:55:58 PM »

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 · « **Reply #16 on:** September 30, 2016, 11:01:14 PM »

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 · « **Reply #17 on:** September 30, 2016, 11:04:18 PM »

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

calj737 · « **Reply #18 on:** October 01, 2016, 03:26:06 AM »

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.

SOHC4 Cafe Racer Fan · « **Reply #19 on:** October 01, 2016, 12:24:13 PM »

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 · « **Reply #20 on:** October 01, 2016, 02:01:09 PM »

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

hashvm · « **Reply #21 on:** October 03, 2016, 09:16:49 AM »

Quote from: calj737 on October 01, 2016, 03:26:06 AM

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 · « **Reply #22 on:** October 03, 2016, 09:17:47 AM »

Quote from: CB750 Cafe Racer Fan on October 01, 2016, 12:24:13 PM

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 · « **Reply #23 on:** October 03, 2016, 09:18:37 AM »

Quote from: Moosey on October 01, 2016, 02:01:09 PM

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

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

hashvm · « **Reply #24 on:** October 18, 2016, 09:35:17 PM »

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

calj737 · « **Reply #25 on:** October 19, 2016, 03:20:26 AM »

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.

hashvm · « **Reply #26 on:** October 19, 2016, 06:42:54 AM »

Quote from: calj737 on October 19, 2016, 03:20:26 AM

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

calj737 · « **Reply #27 on:** October 19, 2016, 07:49:05 AM »

Any tach?

hashvm · « **Reply #28 on:** October 19, 2016, 08:41:40 AM »

Quote from: calj737 on October 19, 2016, 07:49:05 AM

Any tach?

nope, just a speedo

hashvm · « **Reply #29 on:** October 20, 2016, 08:02:55 AM »

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.

calj737 · « **Reply #30 on:** October 20, 2016, 08:18:25 AM »

You should use the stock wire as it does require significant amperage. I believe it's 6AWG equivalent.

hashvm · « **Reply #31 on:** October 20, 2016, 01:41:21 PM »

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

calj737 · « **Reply #32 on:** October 20, 2016, 01:51:07 PM »

Are you planning on running the M-Button?

The open line at th "points/ignition" box, why do you have that? Are you running points or electronic ignition?

You should be running power to the ignition directly from the AUX port. Power to the coils you can run through the KILL switch, but those Emgo switches will probably not enjoy the amperageor long.

The RED lead you have looped from the LOCK port to M-Unit power is wrong. Battery to M-Unit. Key BLACK wire to LOCK.

Have a glimpse at this PDF to tide you over until I finish yours tonight.
http://forums.sohc4.net/index.php/topic,159934.msg1844547.html#msg1844547

540nova · « **Reply #33 on:** October 20, 2016, 02:12:29 PM »

Your solenoid is wired wrong. You can't have the battery and starter motor on the same pole. The left pole, currently going to ground, should have a connection to the starter motor. Omit the ground connection.

Sent from my iPhone using Tapatalk

hashvm · « **Reply #34 on:** October 20, 2016, 02:33:34 PM »

Quote from: calj737 on October 20, 2016, 01:51:07 PM

Are you planning on running the M-Button?

The open line at th "points/ignition" box, why do you have that? Are you running points or electronic ignition?

You should be running power to the ignition directly from the AUX port. Power to the coils you can run through the KILL switch, but those Emgo switches will probably not enjoy the amperageor long.

The RED lead you have looped from the LOCK port to M-Unit power is wrong. Battery to M-Unit. Key BLACK wire to LOCK.

Have a glimpse at this PDF to tide you over until I finish yours tonight.
http://forums.sohc4.net/index.php/topic,159934.msg1844547.html#msg1844547

Hey Cal,
- yes I'm running the M button
- I'll be running electronic ignition (Dyna DS1-2)
- So if I don't the kill switch through the coils 12V should I connect it in series after the ignition switch?
- I have the two colors before the lock to represent the key switch (I thought that's where you connect the key)

Thanks for the PDF and thanks for the help!

hashvm · « **Reply #35 on:** October 20, 2016, 02:34:18 PM »

Quote from: 540nova on October 20, 2016, 02:12:29 PM

Your solenoid is wired wrong. You can't have the battery and starter motor on the same pole. The left pole, currently going to ground, should have a connection to the starter motor. Omit the ground connection.

Sent from my iPhone using Tapatalk

Got it, I'll change that

thanks for the help

calj737 · « **Reply #36 on:** October 20, 2016, 02:59:22 PM »

Ditch the m-button. You'll have relentless issues using it in conjunction with an electronic ignition and those handlebar switches. I know it seems "easier" but honestly, it's much easier and more reliable without it.

Everything on that PDF is relevant to your install, except the Koso gauge wiring. Use AUX to provide "black light power" for your gauges. Also, run AUX to the Dyna.

To integrate your KILL switch:
AUX to Dyna on one branch
AUX to KILL on a separate branch
KILL/RUN to coils (stock BLK/WHT)

So you'll have 12v to coils when RUN is on and KILL interrupts the power to coils.

News:

Author Topic: CB550 - The 1976 brat project (wiring with a M unit) (Read 10562 times)