Author Topic: 1978 CB750F3 rebuild start (Read 8550 times)

majorzozo · « **Reply #50 on:** April 25, 2023, 06:31:33 AM »

Thanks so much HondaMan, greatly appreciated. I will when ready. I am going to risk it for now as I know the engine will probably have to come out for other reasons as well. If it does come out I will probably also change the guides. Currently on a mission to finish, hahaha. Being a first timer I know there are many more obstacles ahead but I couldnt be enjoying it more. Thanks again.

majorzozo · « **Reply #51 on:** April 30, 2023, 10:30:18 AM »

Slow going. I think I will go for the brakes, battery tray, and wiring harness next. Calipers painted with Dupli-Color satin black caliper paint.

majorzozo · « **Reply #52 on:** May 28, 2023, 09:01:43 AM »

All the calipers were wasted. Rebuild kits with new psitons hopefully works with no leaks. Found one of the caliper inner bolts with the rubber sleeve not fitting. Appeared that the rubber sleeve had swollen so it wouldnt fit. Luckily found a used one on eBay that worked. Next I need to figure out the plastic connector on the bottom of the battery tray followed by the wire harness. Also would like to get a new brake line kit if anybody knows who sells. Thanks all in advance as again this iste is priceless.

majorzozo · « **Reply #53 on:** June 07, 2023, 05:26:26 PM »

HI all, would anyone know where the green 90 degree female spade connector goes? From the main harness 3 wires come off in a loom and I believe they attach to the Blinker relay however the relay only has spades for the black and gray. Unfortunately I did not take good enough pictures on disassembly. Cannot figure out from several wiring diagrams. Any advise is greatly appreciated and thanks in advance..

newday777 · « **Reply #54 on:** June 08, 2023, 12:19:33 AM »

That green wire is an extra ground, incase someone wants to use a 3 prong flasher relay.

BTW it's looking good.

majorzozo · « **Reply #55 on:** June 08, 2023, 03:48:24 AM »

Thanks Newday. Greatly appreciated..

denward17 · « **Reply #56 on:** June 08, 2023, 06:16:34 AM »

Good progress, looking good!

majorzozo · « **Reply #57 on:** June 08, 2023, 05:13:26 PM »

Thanks Denward. Slow going as everything takes 4 times longer than it should due to the rust removal. Oil tank next then I should be able to wrap up the rear end and start on the headlight area.

kap384@telus.net · « **Reply #58 on:** June 19, 2023, 01:03:16 PM »

Looking good. Great to see another 'F' bike!

Gamma · « **Reply #59 on:** June 19, 2023, 02:17:22 PM »

Looking good👍

BenelliSEI · « **Reply #60 on:** June 19, 2023, 06:10:56 PM »

Very nice work!

majorzozo · « **Reply #61 on:** July 14, 2023, 02:06:32 PM »

Slow going. Life and the 113 degree heat getting in the way. LOL. Galfer USA had a rear brake line for sale that they said would fit a 1978 CB750F. It was 2 inches too long. When I called them they had me send my original and they manufactured per the sample for no extra cost. Good company and fits well. Next will be bars, dash, speedo and tach followed by the carbs and airbox. Plan to completely go over the carbs which I will assume will take some time.

denward17 · « **Reply #62 on:** July 14, 2023, 04:59:19 PM »

Looking good, yes, those carbs will take a minute

HondaMan · « **Reply #63 on:** July 18, 2023, 08:47:40 PM »

Wow, you came a long way since my last look! It's starting to look 'showroom' again.

kap384@telus.net · « **Reply #64 on:** August 02, 2023, 07:25:55 AM »

Looking great! Keep going!

majorzozo · « **Reply #65 on:** August 17, 2023, 09:38:49 AM »

Hi all,

Running in to some issues. Sent out the front fender support for chrome and came back welded and bent. i guess they thought I wouldnt notice. hahaha. The bigger issue is connecting the wiring at the head light. Notice there are 3 green connectors that house 4 plugs each but they are all the same color. The wiring diagram isnt that clear. It also shows 3 wires coming from the front turn signals but there are only 2. Does anybody know of any simple short cuts for hooking up the wiring? If not I guess I will just have to break out the muti-meter and chase wire to wire to component. Also one of the attach points for the dash light cover is broken and having a hard time finding one on-line. Any advice for the wiring is greatly appreciated and thanks in advance.

newday777 · « **Reply #66 on:** August 17, 2023, 10:58:18 AM »

Green is always grounds.
The front turns have blue and a blue/white stripe and the other side is orange and an orange/white stripe.

majorzozo · « **Reply #67 on:** August 18, 2023, 09:52:14 AM »

Thanks Newday. Think I got it. This is what is left. 1. Exhaust headers and muffler. Headers are waisted but the muffler can be salvaged with a little welding and plating. Understand finding someone to chrome exhausts will be dificult. 2. Painting. 3. Seat. 4. Oil filter housing. 5. Front fender brace and fender. 6. Rebuild carbs and airbox. Keep trying to find the time. Thanks...

majorzozo · « **Reply #68 on:** August 18, 2023, 10:19:58 AM »

Also need to add all the fluids. Not too many like the original muffler but I really like it. Trying to keep as original looking as I can. Just some more pictures.

denward17 · « **Reply #69 on:** August 18, 2023, 10:54:09 AM »

Looking great!

Keep plugging away, you'll get it done.

majorzozo · « **Reply #70 on:** September 11, 2023, 01:27:57 PM »

Hi all,

Have a little quagmire going on as the bike is acting like the excorcist when power is on. When the blinkers are on they work but for the fronts the corresponding other side blinker also blinks but duller. For the rear the tail light also blinks along with the blinkers. Note that the wiring diagram shows 3 wires going to each front blinker but mine only has two.

Also the tail light only works with the key in the park position, not the on position. Every thing else works with the exception of the tach and speedometer lights. The blnkers and both handle bar left and right side switches are new. The handle bars have been re-chromed but done very badly as the chrome is chipping.

Any advice would be greatly appreciated and thanks in advance..

newday777 · « **Reply #71 on:** September 11, 2023, 02:09:50 PM »

Sounds like a ground issue. Run a test ground to the front directional to see if it corrects it.
3rd wire would be a ground.

majorzozo · « **Reply #72 on:** September 11, 2023, 03:16:36 PM »

Thanks Newday. Tried it but no joy. May just start from scatch tomorrow...

tctreppin · « **Reply #73 on:** September 11, 2023, 03:50:54 PM »

Quote from: majorzozo on September 11, 2023, 01:27:57 PM

Hi all,

Have a little quagmire going on as the bike is acting like the excorcist when power is on. When the blinkers are on they work but for the fronts the corresponding other side blinker also blinks but duller. For the rear the tail light also blinks along with the blinkers. Note that the wiring diagram shows 3 wires going to each front blinker but mine only has two.

Also the tail light only works with the key in the park position, not the on position. Every thing else works with the exception of the tach and speedometer lights. The blnkers and both handle bar left and right side switches are new. The handle bars have been re-chromed but done very badly as the chrome is chipping.

Any advice would be greatly appreciated and thanks in advance..

I’ve seen that on a bike I owned , i new the year was correct but the wiring harness didn’t match . A check verified no one had be in there in the past . I search the wiring guide and found the year that resembled mine .
Everyone has answers,here’s mine I have not read this entire thread BUT ,how old is the ignition? Have you disconnected the wiring and cleaned the terminals w/a wire brush?
You mentioned things happening and not happening from the keyed switch position ,which is where I would start my continuity test ,that “blinker” relay could be the home of the gremlins as well
I hope u find it !

Sent from my iPhone using Tapatalk

majorzozo · « **Reply #74 on:** September 11, 2023, 04:50:54 PM »

Thanks TC...Its a new harness but old blinker relay and ignition switch. I am about half way through all the continuity checks and tomorrow I think I will double check the entire harness starting with the head light area. Hopefully I just connected something wrong...I guess no such thing as an easy fix...

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Author Topic: 1978 CB750F3 rebuild start (Read 8550 times)