Author Topic: 69, 69 and another 69 - CB750 projects  (Read 16823 times)

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Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #175 on: March 14, 2023, 10:56:05 am »
This is how far i am at.
I am very bad with taking photos
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline MauiK3

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Re: 69, 69 and a 71 - CB750 projects
« Reply #176 on: March 14, 2023, 03:15:51 pm »
A yellow CBX?
I’ve never seen that.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #177 on: March 14, 2023, 04:01:01 pm »
A yellow CBX?
I’ve never seen that.
PO had painted over the glory red.
It also had a gsxr 1100 headlight fairing, and cheapo turn signals.
I have sourced an original fender. And then bring the tank and cowl back to original colour.
Have a remanufactured headlight shell, turn signals, and fixing the wiring.
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline HondaMan

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Re: 69, 69 and a 71 - CB750 projects
« Reply #178 on: March 20, 2023, 11:06:17 am »
A yellow CBX?
I’ve never seen that.
PO had painted over the glory red.
It also had a gsxr 1100 headlight fairing, and cheapo turn signals.
I have sourced an original fender. And then bring the tank and cowl back to original colour.
Have a remanufactured headlight shell, turn signals, and fixing the wiring.

You are a very wise man...
:)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline MauiK3

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Re: 69, 69 and a 71 - CB750 projects
« Reply #179 on: March 20, 2023, 02:50:08 pm »
Good move on the CBX, they are now quite expensive.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #180 on: March 20, 2023, 04:13:07 pm »
Good move on the CBX, they are now quite expensive.
They are for sure.
I have another cbx, but all i had was a frame and engine with a bad top end.
So that is a restomod project
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #181 on: May 26, 2023, 11:00:15 am »
59 miles on her now
No number pipes, kokusan ignition.
Other than that the bike is original.

Waiting on new brake lines and pads
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #182 on: May 26, 2023, 11:02:26 am »
Rode this beauty to work.

Also 1969.
It has now 160 miles on it, since full rebuild 4 years ago.
K1 forks and fender and HM300 pipes
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #183 on: May 26, 2023, 11:03:19 am »
I wana change the thread name, since there is no 71 anymore, and all three are 69’s
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #184 on: May 30, 2023, 02:42:20 pm »
What needles are supposed to be in 1969 diecast 4 cable carbs ?
Marked B750A, i have 27201 .. are these correct ?

I set the floats a long time ago, so cant remember, but should have set 26mm.
40 pilot, 120 main, clip in the middle.
Air screws, 1 turn out.

Carbs are synced, intake manifolds are new.

Compression is 130psi across

Stock air box filer and hm300 pipes

I do get decel pop, intermittently

Plugs are nice and tan, idles good, strong low and midrange.
Will pull red line 1-3, 4th becomes an effort, but will.
5 th tops out at 6k.

Plugs show lean in fifth WOT.

Carbs are as clean as can be. Brass floats.
I did not replace the floats.

Plugs are suspiciously too tan, i havnt had a cb run this clean plugs ever in low mid range.

Possibly float height low ?
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #185 on: May 30, 2023, 02:45:39 pm »
Even a  mm lower/higher, shouldnt affect this much, ?

Timing is perfect.

Will pull in any gear any rpm, no hesitation.

Just comes to a halt in fifth at 6k.

17/45 gearing

Unless i used a k6 cam lol
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #186 on: May 30, 2023, 02:47:07 pm »
And my compression gauge always reads lower.
This is a fresh engine, nice and tight
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #187 on: June 19, 2023, 09:41:14 pm »
Surprising how similar they are  ;D ;D
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline RAFster122s

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Re: 69, 69 and a 71 - CB750 projects
« Reply #188 on: June 19, 2023, 10:52:36 pm »
I wana change the thread name, since there is no 71 anymore, and all three are 69’s

I’ve been told the thread owner can edit the first post and change the thread title that way…
Subject line should be editable also…
David- back in the desert SW!

Offline Salman_z8

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Re: 69, 69 and a 71 - CB750 projects
« Reply #189 on: June 19, 2023, 10:57:29 pm »
I wana change the thread name, since there is no 71 anymore, and all three are 69’s

I’ve been told the thread owner can edit the first post and change the thread title that way…
Subject line should be editable also…

Perfect
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Online BenelliSEI

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Re: 69, 69 and another 69 - CB750 projects
« Reply #190 on: June 20, 2023, 05:20:45 am »
Do you have the rubber gaskets installed, under the carb tops?

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #191 on: June 20, 2023, 10:41:33 am »
Do you have the rubber gaskets installed, under the carb tops?

Nope, i never saw any installed in the three sets that i have.
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #192 on: June 20, 2023, 10:43:09 am »
Do you have the rubber gaskets installed, under the carb tops?

Funny thing is, identically set carbs, are lean on one bike and rich on the other lol

Both have no gaskets under the top
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline HondaMan

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Re: 69, 69 and another 69 - CB750 projects
« Reply #193 on: June 21, 2023, 06:25:29 pm »
What needles are supposed to be in 1969 diecast 4 cable carbs ?
Marked B750A, i have 27201 .. are these correct ?

I set the floats a long time ago, so cant remember, but should have set 26mm.
40 pilot, 120 main, clip in the middle.
Air screws, 1 turn out.

Carbs are synced, intake manifolds are new.

Compression is 130psi across

Stock air box filer and hm300 pipes

I do get decel pop, intermittently

Plugs are nice and tan, idles good, strong low and midrange.
Will pull red line 1-3, 4th becomes an effort, but will.
5 th tops out at 6k.

Plugs show lean in fifth WOT.

Carbs are as clean as can be. Brass floats.
I did not replace the floats.

Plugs are suspiciously too tan, i havnt had a cb run this clean plugs ever in low mid range.

Possibly float height low ?

Do you have all 4 of the carb's vent hoses routed up and over, behind the airbox? If these are too short or in turbulent air it can affect the torque, especially at high speed, because it reduces the bowl's ability to push fuel up the jets.

Another thing that can cause poor top-end performance (if carb-related) is fuel delivery, either from a [partially or fully] blocked fuel tank vent (in the fuel cap). This slows fuel delivery, especially in fast-moving air around the tank (which is then at lower pressure than still air).

I've also seen the [brass] floats set incorrectly for the K0/1 bikes. They should be staggered 1mm between them, with one float (kickstand side of the bike) at 25mm and the other at 26mm. This was true until the 657b series carbs with the plastic floats came out, around 3/1972.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #194 on: June 22, 2023, 09:50:21 pm »
What needles are supposed to be in 1969 diecast 4 cable carbs ?
Marked B750A, i have 27201 .. are these correct ?

I set the floats a long time ago, so cant remember, but should have set 26mm.
40 pilot, 120 main, clip in the middle.
Air screws, 1 turn out.

Carbs are synced, intake manifolds are new.

Compression is 130psi across

Stock air box filer and hm300 pipes

I do get decel pop, intermittently

Plugs are nice and tan, idles good, strong low and midrange.
Will pull red line 1-3, 4th becomes an effort, but will.
5 th tops out at 6k.

Plugs show lean in fifth WOT.

Carbs are as clean as can be. Brass floats.
I did not replace the floats.

Plugs are suspiciously too tan, i havnt had a cb run this clean plugs ever in low mid range.

Possibly float height low ?

Do you have all 4 of the carb's vent hoses routed up and over, behind the airbox? If these are too short or in turbulent air it can affect the torque, especially at high speed, because it reduces the bowl's ability to push fuel up the jets.

Another thing that can cause poor top-end performance (if carb-related) is fuel delivery, either from a [partially or fully] blocked fuel tank vent (in the fuel cap). This slows fuel delivery, especially in fast-moving air around the tank (which is then at lower pressure than still air).

I've also seen the [brass] floats set incorrectly for the K0/1 bikes. They should be staggered 1mm between them, with one float (kickstand side of the bike) at 25mm and the other at 26mm. This was true until the 657b series carbs with the plastic floats came out, around 3/1972.

Yes, vent hoses are routed behind airbox.
Petcocks is clean, tank is a yamiya replacement.

The only thing that comes to my mind, well two things;

One of my k0’s has its original camshaft, the other one .. cant remember, may be a k4-k6 ..

Secondly, i saw you mention fuel level in the bowl should 3-4mm, below gasket seam, but at 26mm, its more like 10mm. More a pull up, the richer it gets.

Ot may be i should try raising the fuel level to 4mm, go down a notch on the needle, and perhaps go to a 115 main ?

Both bikes have 4 cable carbs, one has early correct cam, and some intake port work, runs a little rich but more power everywhere, compared to the other, but the other does have perfect tan plugs lol well a tad rich lol

Is there an aftermarket cam which is kinda similar to the early cams ? 

69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #195 on: June 22, 2023, 10:18:59 pm »
Where is the fuel level supposed to be, at 26mm ?
4mm below the seam ?
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Online BenelliSEI

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Re: 69, 69 and another 69 - CB750 projects
« Reply #196 on: June 23, 2023, 04:17:21 am »
I was never able to synchronize my K0 carbs, with any consistency, until I installed those top gaskets. Why leave them out?

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #197 on: June 23, 2023, 12:02:45 pm »
I was never able to synchronize my K0 carbs, with any consistency, until I installed those top gaskets. Why leave them out?

I can get them synced pretty good, but i will try the gaskets.
I never put em in, just because all the ones i have taken apart, never had them.

Will try that
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #198 on: June 23, 2023, 03:24:32 pm »
Since, the bike in question has an unknown cam, stock honda, but of unknown year, could that make a difference ?
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track

Offline Salman_z8

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Re: 69, 69 and another 69 - CB750 projects
« Reply #199 on: June 23, 2023, 03:27:08 pm »
Took the other bike out, and it is so effortless to accelerate.
It does have some mild intake port work.

Now i want both of em to be similar.

Both have same airfilter, same oil, b750A carbs, similar jetting, same electronic ignition.
One has yamiya no number pipes, other ( the one in question ) has later hm300
69 CB750 - Candy Red - Complete and Running
69 CB750 - Candy Blue Green - future
69 CB750 - Candy Gold - Complete and Running
79 CBX1000 - Candy Glory Red-
80 GS1100E - old friend
And some more … i lost track