Author Topic: First build: CB750 K3 cafe  (Read 19393 times)

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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #50 on: July 24, 2016, 07:39:32 AM »
I got the new coils and wire harness. I took the old ones of the bike today. Harness and rectifier were melted quite badly. So I have to find a new rectifier asap.







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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #51 on: August 05, 2016, 08:15:23 AM »
About the damaged tank. UPS won't cover it. They said that the package didn't meet their instructions. The tank was one of the best packed things I have seen, but that wasn't enough. So there is not mutch I can do. Luckily I have a friend who is a very good painter so hopefully I get that fixed.

Every electronic part has arrived and today I was looking forward to get the bike running again. Set everything up (coils, Hondaman ignition, new regulator and rectifier, fusebox and harness.) No spark. It cranks ok. I couldn't solve the problem. Every part is new out of the box, but I quess I have to test them that everything works.

There was one mystery wire in the headlight bucket. Brown/blue. From the right hand switch. Did some search and some say this is turn signal buzzer wire. Some say it's horn. There was one free wire in the bucket that was coming from the harness. Brown. I assume thats going to breaklight. But I didn't have any wire to match that color. I have a diagram. K1-k2. Diagram says that the brown goes to combination switch. I assume it is the off/on/off switch? I was hoping that this would be an relatively easy task...

Cleaned the solenoid:






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Offline 540nova

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Re: First build: CB750 K3 cafe
« Reply #52 on: August 05, 2016, 08:36:31 AM »
Put an ohm meter across your mystery wires, and start pushing buttons. If you get continuity, you've found the switch.


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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #53 on: August 13, 2016, 09:43:59 AM »
I tried to start the bike without Hondaman's ignition and the bike fired right up. So those coils are ok. The problem is that with the ignition connected it won't give spark from the 2-3 cylinder coil. I filed the points and cleaned them but no success. So I will keep the ignition disconnected and ride a bit and try it again. I also have another problem with the headlight. It won't come on. New halogen. I even opened the switch to check if the reason is there. Everything seemed to be ok. Cleaned everything and painted the housings while I'm at it.

I also synced the carbs the best I could. I found out the other day that there is gas in the airbox so there is something wrong with the floats or something related. So there is some things to take care of before the first ride.

Tach cable is leaking oil where it connects to the motor. I changed the seal for it before. I took the old one out too. Any ideas how to stop the leak?







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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #54 on: August 19, 2016, 10:13:32 AM »
I got some painting finished today. Right and left hand switches. I used fluorescent orange for the texts and Testor bright red for the knob. Under the semi gloss black is primer. I used primer also on the knob. If you are doing this you must get a detailing pen for the letters. It is impossible to paint the letters without it. I'm really happy with the result. I hope the paint holds up. Paint is waterbased acrylic paint from local hobby shop.








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« Last Edit: August 19, 2016, 10:18:29 AM by -JP- »

Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #55 on: August 29, 2016, 07:42:17 AM »
I had some trouble with the left hand switch:

http://forums.sohc4.net/index.php?topic=160250.0

Horn still doesn't work. I don't know what is wrong with it. It works when I connect it to battery, but not from the switch. I leave it that way for now.

There was also some problems with the headlight wiring. Headlight didn't come on. Now it is solved too. Not exactly like the diagram shows, but all lights work for now. Is the parking light in the headlight meant to be on when the headlight is on H or L? Mine is on in both positions.

I also changed new clutch cable and assembled the sidepanels.

Still waiting the tank from the painter. I really hope that the result is good.





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Re: First build: CB750 K3 cafe
« Reply #56 on: August 29, 2016, 08:37:14 AM »
Nice looking covers.
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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #57 on: September 04, 2016, 02:21:21 AM »
I got the tank from the painter and the result is outstanding. Installed the gas cap and petcock. When I put the tank on the bike I noticed that the petcock hits the carb lifter arm. Not much but enough to make the throttle bind. I hope I can move the tank forward a bit cutting the rubber cushioning. If that doesn't work this can be a big problem.







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Offline calj737

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Re: First build: CB750 K3 cafe
« Reply #58 on: September 04, 2016, 02:24:20 AM »
Paint looks really beautiful.

Worst case scenario, cut the pegs off the frame (the steel pins that the rubbers slip over) and move them forward, then reinstall the rubbers. If you have to weld them on, you'll only have a very small area of the frame to touch up and it will be beneath the tank and steering so it won't be obvious.
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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #59 on: September 04, 2016, 02:27:53 AM »
Paint looks really beautiful.

Worst case scenario, cut the pegs off the frame (the steel pins that the rubbers slip over) and move them forward, then reinstall the rubbers. If you have to weld them on, you'll only have a very small area of the frame to touch up and it will be beneath the tank and steering so it won't be obvious.
Thanks a lot. Good idea. Will look in to that.

Offline 754

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Re: First build: CB750 K3 cafe
« Reply #60 on: September 04, 2016, 01:59:05 PM »
Should be clearance there .i would leave the mounts and grind off the petcock. Maybe..
 Can you shift tank to he right on rear mount ? Is petcock aftermarket ?
Nice paint, really like that..
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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #61 on: September 04, 2016, 09:57:48 PM »
Petcock is original. There is not mutch to grind. I cut those rubber cushionings a bit and the tank moved forward a bit. Helped a little. Fuel line is still touching the arm mildly. Petcock is clear now. I'm trying to find fuel line that has smaller outer diameter. There is not mutch to move side ways in the rear. There is this rubber where the lip goes in and it keeps the rear in place. I will check that again.

Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #62 on: September 05, 2016, 01:11:52 PM »
I got the petcock issue sorted out. Smaller fuel lines and i moved the tank a little to the right from the back.

There was an issue with the handlebars hitting the tank so I had to make stoppers to limit the movement. I cut a wheel balansing weight in half and glued the pieces to the stoppers.

Filled her up and it was time for the first ride! Being familiar with todays superbikes braking performance it was some what a mix off fear and happiness to get on the road. Well, the brakes are what they are. I have to admit that some kind of upgrade might be coming in the future. Maybe dual disc setup or something. I know I have to get used to this bike and get some kilometres on it. This was just a short ride around the block. But it was a nice one after all the work from the spring.





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Offline calj737

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Re: First build: CB750 K3 cafe
« Reply #63 on: September 05, 2016, 03:04:43 PM »
I don't think I'd rely upon glued on steering stops for a long term solution. Best to drill small holes in the lower clamp, then thread in some Grade 8 socket heads with LocTite on them.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #64 on: November 20, 2016, 01:11:23 PM »
It's been a while. Little pause on the project. I had plans to rebuild the engine this winter, but I will not. It will be done, but not now. But I still have a little to do list.

Wheel bearings
Wheel lacing
Swingarm powdercoat and bushings
New exhaust (old one is full of dents.)
Maybe clip-ons

I was thinking about painting the wheels black, but I'm not sure is it a good thing to do because there are spokes and maybe they can't be adjusted anymore after painting. I bought an old 1.85-19 inch front rim. I had an 18 inch rim on front witch I can now move to rear. My old rear wheel was 16" harley wheel. So I' m getting the oem style now. Bought continental rb2 & k112 tyres to mount on them.


Delkevic makes a nice short exhaust for these bikes and it's stainless and the price is also quite cheap. Original exhaust would be my choise, but those cost a fortune.

So a little update whats going on.

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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #65 on: November 29, 2016, 11:48:06 AM »
Yesterday I replaced wheel bearings. Front axle nut was a pain to get off. Lots of heat and hammering and it finally loosened. I also took the wheels out for lacing and swingarm is getting a powdercoat. I also cleaned the rear brake drum and lid.





I still have to figure out what kind of rear shocks should I get. I got spare Konis and I sent them to be serviced. Turned out that rods are damaged and have to be replaced. The coating on the rods is coming off. So they are not sealing properly. If Ikon can't provide the rods as spare parts cheap I have to buy new shocks. I think I stick with Ikons because I like how they look and I have been reading good things about them. And those can be serviced and are quite cheap.

Left one is Koni. The right one is unknown brand:



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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #66 on: December 30, 2016, 10:48:00 AM »
I got the swingarm from the powdercoat. Installed bushings for the shocks. I also received exhaust flanges and Ikon shocks. Delkevic exhaust is on it's way.

I would like to clean the rear of the bike. Get rid of the fender and make a new seat. Two seater, but lower. Maybe clip ons too. We'll see...






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Offline riverfever

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Re: First build: CB750 K3 cafe
« Reply #67 on: December 30, 2016, 01:11:13 PM »
Very cool that you and your dad are tackling this together. That paint looks absolutely dynamite! Hey you never mentioned if you got another brake bleeder screw. Do you need one? I have one that is for a 750 which is way bigger than the 550 and I didn't know that years ago when I ordered. Yours if you need it JP.
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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #68 on: December 31, 2016, 01:10:06 AM »
Very cool that you and your dad are tackling this together. That paint looks absolutely dynamite! Hey you never mentioned if you got another brake bleeder screw. Do you need one? I have one that is for a 750 which is way bigger than the 550 and I didn't know that years ago when I ordered. Yours if you need it JP.
Yes, I got a new bleeder screw. It was bigger than the old one, but it works fine. Thanks a lot anyway.

It's been fun to build this bike with my dad. And the project is far from over. We are going to rebuild the engine in the near future. So lot's of hours still left with the bike and the old man.

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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #69 on: January 06, 2017, 09:37:54 AM »
Today was painting day. Some sections of the frame were taken a beating so I applied some fresh paint to make it look good again. I'm happy with the result. Tomorrow I will mount the swingarm and those new shocks.



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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #70 on: January 19, 2017, 12:39:29 PM »
Wheels laced and rubbers mounted. Some painting with tyre pen. Ikons mounted. These shocks really match the old look of the bike. Tank decal attached. Exhaust will be mounted next.




Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #71 on: January 22, 2017, 05:33:06 AM »
Today I installed exhaust system. Like I mentioned it is Delkevic stainless system with shorter silencer. I've read good reviews about this system and how the installation should be peace of cake. Well I had trouble. I managed to get it right but I think one of the headers might be bent just a little bit off. I had a hard time getting the headers in the collector. Finally after 1,5 hours I got it to fit.

The exhaust itself is a quality item for the price. Nice welds etc. There was no instructions with it. Everything was nicely packed. I can't say how it sounds yet, but I like that there is a removable baffle. I left it in place. I rode with straight pipe last summer and the noise was too loud for me. So my ears will probably love this pipe.

I really like the looks of it.













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Offline calj737

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Re: First build: CB750 K3 cafe
« Reply #72 on: January 22, 2017, 06:53:22 AM »

The welds on this joint actually look pretty suspect. Overall, they look decent/good. See the way the tube is "cut away"? Thats referred to undercut and is the result of insufficient filler wire when welded. You might encounter a crack here in the future. If so, a competent TIG welder in your area can clean it, weld it, and you'll be back on your way!

For fitment, its generally easiest to locate the header pipe with the flange loosely fixed. Then, connect the collector, then snug the head bolts. Attach/hang the muffler last. It can still be tricky without a second set of hands no matter whose pipes and how much you cuss at it  ;)

But they sure look great on your bike!!!
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #73 on: January 22, 2017, 09:27:59 AM »
Thanks for the heads up. I'm no welder but I understand that these welds are not the best on the market. I've had Yoshimura Japan and Racefit systems and those are art compared to this. But for the money these are quite good stuff. Or I suppose...

I tried to put it on just like you discraiped. Loosely. Eventually got it. I almost gave up. Broke one of the springs too. Just snapped. I have to keep an eye on those welds now and then. Thanks.

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Offline -JP-

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Re: First build: CB750 K3 cafe
« Reply #74 on: January 23, 2017, 09:31:04 AM »
There was an old steering damper in the boxes that came with the bike. I used pipe clamp to mount it on the frame. Maybe not the cleanest, but works ok. One question came up. Is it ok to mount this stiff or should it be loose/wobbling a bit?