Setting points 1974 CB750 K4

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Setting points 1974 CB750 K4

JonathanHValencia

 Hey folks,

I’m having the hardest time setting up timing to be just right on my cb750. I’m using the circuit light method, and cranking with a wrench. My circuit light seems to stay on, or not come in once I cross the F (fire) for 1-4 when I’m working on the 1-4 side. Can anyone help with this? I’ve watched videos, read manuals. Bought a new circuit light to do this, but the light seems to work fine, just can’t set up the damn timing and in the process I threw it off my points. Can’t keep my bike running now. Maybe low battery from messing with it so much. I’m having no luck, and I don’t want to wear out the bolt with crank, it looks abused already. The circuit light method looks easy online, I follow exact directions but to no avail.

https://m.youtube.com/watch?v=gjS-v7cMFPI

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Re: Setting points 1974 CB750 K4

TOOLS1
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OK here is the easy way to do it. First you need to disconnect the wire from the coils to the points. There is a connector behind the airbox/oil tank where it is easy to just unplug them. Then set the point plate adjustment slots right in the middle of the slot. Now set the "1-4" timing mark at the line. Now hook the test light wire to the "+" battery terminal. Touch the light to the point wire connection, and adjust the points to where the light just goes out. Now repeat with the "2-3" set of points. You will have maximum dwell and your timing will be spot on.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: Setting points 1974 CB750 K4

JonathanHValencia
Ok just to make sure I have this right.
Disconnect the wire from the coil to the points, that’s the blue and yellow electrical wire just behind my oil reservoir that traces back near the battery

Then place the opening of the point plate just over the viewing area with the marker tab

So now I set the timing mark for cylinders 1-4 on that mark
Do I place it on the F or the T?

So one side of the test light to the positive battery terminal and the other side to the point wire connection, which side? There is an alligator clip and a ground.

So now I need to adjust the plate until the light just goes out, then I screw in the plate and move onto the smaller 2-3 plate .
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Re: Setting points 1974 CB750 K4

TOOLS1
Administrator
All most right. You can connect either end of the test light to either place, it will not matter to it. I would connect the gator clip to the "+" terminal and stick the pointed end onto the wire connector after unplugging them. Then you set the point plate to where the screw at the top is in the middle of the slot. Then set the moveable part for the other set of points to the middle of its slot. Now FORGET what you saw on youtube!!!!!! Rotate the crank until the "F 1-4" is in line with the timing mark. Now go to where you adjust the point gap and move the points (as adjusting the point gap) until the light just goes out. The timing is set!!! Now go to the "F 2-4" and do the same with the other set. Be sure to move the test light to the other wire though.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: Setting points 1974 CB750 K4

JonathanHValencia
So just set and screw the points plate to where the screw is centered? Then only adjust the points gap itself until the light goes out? Thought they had to be adjusted and gapped separately outside of the timing

Sorry I’m having trouble understanding. The points are so frustrating for a newbie
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Re: Setting points 1974 CB750 K4

TOOLS1
Administrator
Points are actually very simple. The thing about points is you have a range for the dwell. It is not as important as timing. You can change timing without affecting dwell, but you cannot change dwell without affecting timing. What you are doing with my method is fine tuning the timing with the dwell setting. Also you will be setting the points for the maximum amount of dwell, which is what you want for the best performance with a points ignition.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: Setting points 1974 CB750 K4

JonathanHValencia
Morning,

No luck. With the two cables disconnected from power my having one side of my continuity light hooked up to the battery and the other side on the point, it wouldn’t light up
Maz
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Re: Setting points 1974 CB750 K4

Maz
If one side is connected to  battery positive and the other side to the moving 'arm' of the points, the lamp should light whenever the points are closed. Touch the wire to ground to check the bulb . If it lights up,  connected between positive and ground,  then it would suggest that your points are badly corroded or not closing. Also possible is that the points backplate is not grounded properly or your test lamp is an LED , which will only work when connected the correct way round - Red to positive,  Black to ground.
Maz
'76 CB500T
'75 GL1000 'Wing
'79 CB750L
'90 FJ1200

In a little place called Bexley, Kent, UK (Just south of London!)
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Re: Setting points 1974 CB750 K4

JonathanHValencia
Backplate isn’t grounding? I did notice it sparked if I touched it with the screw driver. What would tell me it isn’t grounded and how is t grounded?
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Re: Setting points 1974 CB750 K4

TOOLS1
Administrator
It is grounded by touching the the engine case on the back side. If you have the test light clipped to the "+" terminal (and the battery has a charge) the light should come on when you touch a ground, it can be the "-" on the battery, or the frame, or the engine case... If you have it hooked to the battery "+" and it does not light up when grounded, you have a bad light, or dead battery. If it is working correctly, and you have it on the correct set of points for your firing mark, and it is not coming on, then like Maz said, you either have the points open (adjust them so that the light comes on), or your points are really corroded/dirty (clean them with some fine wet/dry sand paper.  
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)