Topic: My first bike: '78 CB750k

[iron_worker]

The speaker is the turn signal beeper if you hadn't figured that out already. lol

IW

[Stev-o]

The speaker is for the CB radio!

[fendersrule]

Didn't get too much done today; had to work some on the girlfriend's car. But I do have a question below.

Let's kick some butt on the rear brake hub.


New shoes installed. New cotter pins installed. But something tells me that not only do I need to grease the face of the shoe shaft, but also the shaft itself. Let's remove it.


Probably not a bad idea.


But then I found out that I obliterated what seemed to be a paperish seal ring that sat in the back. Now I gotta figure out what to do.


Everything is greased up and good to go. This hub got some nice cleaning treatment. Used regular brake grease on all touching metal parts, a small amount. Used waterproof "racing" grease on the shaft itself, which had some slight hesitation to move before. That could probably explain why the rear brakes were acting the way they were (slight sticking after application); should be all golden now.


But what to do about that paper ring thing, which is the rear cam seal. Honda part only? Either way, I went ahead and ordered this.

[fendersrule]

I wanted to bring the electricals back up into discussion. I have that nice diagram printed on D-sized paper, and it hangs above my work desk now. Thanks Steve-o!

"I need to figure out what the hell is going on with my turn signal wiring. Left blinkers work (front and rear), but you have to get it in the right position. Too Far left throws off a steady buzzer, while losing the signal to the lights. Far right throws off the same steady buzzer. I've yet to see any of my right turn signals work, front or rear."

What should be the expected switch behavior in these things? If you crank the switch all the way to the left or right, I would expect the blinkers to still work. Is the steady buzz normal behavior? I believe that's probably just something to let you know that the blinkers are on.

If that's the case, then the blinkers are simply not coming on in this state at all.

Once I leave the far left state, my front and rear right blinkers suddenly appear and function normally, although the buzzer is gone.

Once I leave the far right state, nothing appears on the front and rear left blinkers, although the buzzer is gone.

The running lights work.

Anyone have any guesses?

1) Trace test the connection of the wires to the right blinkers.

2) If that fails, then take a closer look at the switch. I did already pull this apart and sprayed some contact cleaner on the teeth in the switch. It appears that it mechanically functions.

[madmtnmotors]

But what to do about that paper ring thing, which is the rear cam seal. Honda part only? Either way, I went ahead and ordered this.

The original was felt and serves as a rudimentary dust seal and if lightly oiled can serve to lube the brake cam shaft. Good to have.

[fendersrule]

Not too much to report on. Still waiting on that damn dust seal. Figured I'd slow down a bit, otherwise I'd have nothing to do for the rest of the winter with the speed I've been going.

Paint and body is going to be the last phase at the end of the winter, if all goes well. I've changed my mind on the paint. Going from "Freedom Green" to "Valley Green Metallic." I've also did some wire-wheeling + POR15ing as a temporary solution to some parts of the bike. I redid the swing arm, and several welding seams on the frame. In the end, I want to have it all apart and blasted, but that's too much of a task this go around. The good news, is that there's only surface rust here and there. Wire-wheeling gets right of almost all of it. Glad to know I don't have a rust heap!

Still would like to get the wiring with the blinkers worked out, as that's something that is definitely keeping it "unsafe" on the road.  If you guys have any guesses based on the description I have, please feel free to chime in.  Otherwise, I'm going to get together with a friend and start.

I had my GF do the emblem work. Seemed like a fun task to pawn off. It came out really well!




I think she used etch primer, and cut out masking tape to go around the letters. Sprayed with flat black enamel. Removed teh tape, and used some "go-gone" to clean up the letters. Turned out as good as I would have done it!

Before:


After:


My bike finally has a full face, where it had nothing when it arrived. No turn signals, chopped off turn signal mounts on the ears, no headlight reflectors, and no fork emblem. It's now 100% complete.

Then I got really bored today.

Before:


After:


The covered shocks are a must for a CB IMO. Never did care for the pogo-stick look of the stock shocks.

[Stev-o]

I like the Valley Green, my K2 has the original paint. Look here...

 http://forums.sohc4.net/index.php?topic=61168.11200

Your girl did a nice job, you should've snapped a pic of her painting....ha!

[fendersrule]

Well, even with the diagram, I feel a bit lost still. I'm a wiring noob, big time.

Here are the only "unplugged" wires I have found:

Brown wire in the headlight area (with duct tape around it..ignore that black wire that's in the background):


This green wire looks like it plugged into somewhere, but I don't see a slot for it on this black piece.


Any ideas? The turn signal system is all screwy.

I'll be out in the garage, periodically checking responses. The best I can do is stare at things hoping to find a magic answer.

[fendersrule]

Well, I have the turn signal switch apart, and for some reason after taking the switch apart, I'm able to activate the left turn signals. It works as expected...clicking noise from under the seat, and a the speaker actually comes on (first time I've ever heard it...frigging loud and obnoxious).

So there's something going on with either a short at the switch, or a something else. The right blinkers remain dead, which I believe to be a separate wiring issue.

Tonight I'm going to conclude that I should start off by replacing my ignition switch, being that I have to get it "just right" on the "on" position. Takes a lot of jiggling. I'm thinking that it may alter the behavior of the signals.

I'm only assuming that the ignition switch should be replaced if you have to do a lot of "jiggling" around the ON position. Anyone have any experience doing that?

[fendersrule]

I really would hate to wait until next Monday to receive this thing, it just shipped.

Would any part store have this, or is this specifically a Honda part? If so, I can just call a few places here in town.

[Mr Freeze]

Hey. I got a few pointers for you.

As far as the ignition goes. I have a 78 cb750 also and had the ignition switch crap out on me on the road. Basically I turned the bike off to pump gas and upon turning the key back on the electronics wouldn't come back on. Luckily I was able bypass the switch and get home. Turns out one of the spring loaded contacts was jammed down hence no electrical flow. The switch is cheap enough to just replace.

So.

You'll have to unbolt the bracket with you speedo and tachometer on it to remove the ignition key cylinder.  Once you get the cylinder out you'll see the white switch attached to the back of it.



You only need to buy this part.



Throw some grease between the inside of the lock cylinder and the switch and you're done.

As far as you turn signal problem. That part you pulled is the signal flasher relay. If the lights come on, but don't blink, this is a sign that the relay isn't working to make the bulbs flash, which is why they are constantly on. That looks aftermarket because the originals looked like this.



Try swapping the black and gray wire on the terminals and see if that works. It's possible the person who installed it did it backwards. The green wire that is hanging isn't supposed to go to anything. It's kind of just there and some newer flasher relays will actually have a ground lug you can attach it to.

You can replace the relay with any sort of 2 wire automotive type although you have to observe the in/out configuration so that the relay had the load coming in properly to flash the turn signals. The load side on the Bike is black. I actually have an OEM Honda one if you want it, since I've replaced my blinkers with lower profile LED types the original relay no longer worked. It's in great shape.

[fendersrule]

Thanks so much for that reply. My father is coming into town, and he's really ready to get his hands dirty with the electrics. We will take a look at all that, and use your insightful post as a reference. It's good to know that maybe we just need to replace that white part, and not the whole ignition itself (I found that part at a website, so I'll get it ordered). It sounds like I need to get this done before the bike hits the road so I don't end up in the same situation as you!

The turn signal we seem to have isolated down to inside of the switch housing (something isn't being grounded as the switch housing is sparking with the handlebars). Sometimes the "buzzer" comes on, some times it doesn't. But I think we've isolated the problem enough so we know where to look. I think the relay is fine, even if it isn't stock. The blinkers work just fine, as long as the electrics are left out of the switch housing.

The problem with the right blinkers not coming on was fixed-- there was live wire being exposed to the frame from the rear turn signal (the wire was getting pinched in the mounting area).

I do have one question: My seat just came in. Wow, it's in great condition (pics to come later)! The only thing, is that the chrome buckles have some pitting going on. I can clean it up real good and it will only look "ok" but eventually I'd like to replace the buckles.

in order to replace the chrome buckles (which I can actually just pull from my '78 seat), does the seat cover have to come off? If not, then I can easily get started on this today and have that new seat on there. The underside doesn't even need to be cleaned nor powder-coated either! I also found a '77 Owners manual in it.....

[Mr Freeze]

You shouldn't have to pull the seat cover. The buckle is held on with a machine screw that threads into the seat pan and has a little safety clip at the end. If you want just the buckles though, you may find that the new seats strap has to be re sewn to the new buckles since the 78 has more of a hump that the 77.

[fendersrule]

Yea. I'm assuming the buckles are the same with the '77 and '78 (I didn't measure, but they look to be the same).

There's the machine screw that screws into the seat frame, with a safety clip on the back. But if you look above that, there's a "button" that appears to also go into the seat as well. That's what I'm concerned about...does that just "pull out"?

I don't plan on replacing the strap...I just want to swap the buckles. I haven't looked close, but is the strap actually sewn around the buckle? If so, this would be a simple task for a re-upholstry shop to do. Probably would be less than 20 bucks to have done.

That's all this '77 seat needs. It's really in fantastic shape.

[wheeliepop]

Hey Bud,

I was just playing around with my blinkers and the spaghetti behind my headlamp yesterday! Do you have a manual yet? Pretty useful, especially since you are going deep and long on this project.

I'll keep an eye on your project and help you along if I can. Great looking K!

And don't feel bad, I like that tank scheme!

[fendersrule]

My '77 seat came in today. I got it for about $50 from a nice dude down in Florida. A huge thanks to him for giving me a steal. See what you think:




It's so nice to see a straight seat. The profile of the '77 is just unbeatable:


I also never cared for how the '78 seat also sat over the tank more. Just personal preference:


A preview. Wow, what a difference:



It's time to get work on removing the hardware on the '78 seat. We also want to replace the seat latch for a good measure, and do some minor repainting. All of the buckle screws needed to be extracted on both seats. Fun stuff.





And a nice bonus:



All of the '78 hardware is now soaking in vinegar. Tomorrow I will do the same to the '77 seat, and then transplant. I'll also polish some things up, and install the new latch, paint the hinges, and then mount 'er up!

[Stev-o]

Looks good, great deal.  Thanks to the cafe guys who take the stock seats off, there are still some good seats out there. My K8 seat came from FL too. 
New buckles are available if yours don't turn out good.

[iron_worker]

I have to do the same thing to my seat. I thought that buckle was riveted on so it's good to know it's threaded. I was wondering how I was gonna do that.

IW

[fendersrule]

Had a long day at work, but I still managed to get some things done.

When replacing buckles, there's a high probability that you will have to use an easy out, along with an hour of patience on the buckle screws. Even if they don't look corroded from the outside, this still applies. After breaking both in my '78 seat, I went down to a specialty shop and made an appointment to have my '77 bolts removed, and to add a new tap. When I got home I thought that I should save that $65 and not bring my seat in next week. After getting started, believe it or not, with a pair of vice grips and some penetrating oil I was able to remove one screw. I couldn't believe it! I'm finally 1 for 2! Well, hopefully the other one will go smooth....


Nope. As you can see, I've had to drill the hell out of it and insert an easy out. Just like the others, an easy out wasn't enough to remove it.


Several minutes later, it was decided to drill through it.


Threads were removed.


Damn bugger!


And there you have it. The threads are still intact. $65 saved. Just now gotta go get some replacement screws at the hardware store tomorrow, and put the strap back on!

About that darn strap...


Here's after the donor hardware looked after a night of soaking.


Prying the metal clip off of the 77's strap so that everything can slide off.


Tightening on the new stuff. It's really all pretty straight forward. Use a bench vice to hold the "button" bolt in place so you can unscrew the nut that's behind it.


All done!

More to come. This seat will be a winner real soon (as if it weren't before...

[andy750]

Subscribed. Enjoying this thread and the progress you are making . Also looking forward to see how the bike turns out.

Thanks
Andy

[fendersrule]

* Cleaned all hardware
* Repainted the hinge the POR15. Applied some grease.
* Replaced the latch with OEM Honda Part
* Deep cleaned and polished the seat
* Fully mounted and installed









Notice the two "marks" above the seat on the tank. That's where the '78 seat ended.

[Stev-o]

Wow - polished the seat? Nice.    Now I will have to do mine!   What color are you painting? 

[seanbarney41]

might want to make sure your wearing some sticky pants the first few times you hit the gas on that shiny seat

[madmtnmotors]

might want to make sure your wearing some sticky pants the first few times you hit the gas on that shiny seat

I can vouch for that! I used amour-all on my seat once...












AND ONLY ONCE! 

[seanbarney41]

now that I think about, a fast stop is worse!