new harness now bike wont run just back fires 76 cb750

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new harness now bike wont run just back fires 76 cb750

globalfastener
so i took this bike in. it did not have an ignition, just a toggle and a start button.   the bike ran fine. i installed new harness and handle switches.  i have three extra wires coming from the left switch(one i assume is the horn which this bike does not have) the other two i dont know.  there is also a blue wire coming from the indicator lights that does not have a home.

anyway, the starter switch will crank the bike but all i get is the occasional back fire.  it will backfire even if the switch is in the off position.

everything is color coded on the harness so i am certain i have everything plugged in right.  i do plan on finding a wire diagram to be certain. all the plugs are firing but the bike wont start.

any ideas?
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Re: new harness now bike wont run just back fires 76 cb750

TOOLS1
Administrator
Reverse the coil wires. Is the wire to the indicator lights light, or dark blue? What are the colors of the other wires? The horn is light blue. The other horn wire is a (hot) black wire.
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: new harness now bike wont run just back fires 76 cb750

globalfastener
i believe its a dark blue wire.  i will try and reverse the coil wires when i get to the shop....i had thought of that earlier tonight...but i am certain i hooked them up the way i un-hooked them.  You know how that goes though
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
i should be looking at the k6 diagram right?  it shows the horn is green
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Re: new harness now bike wont run just back fires 76 cb750

TOOLS1
Administrator
The dark blue is the high beam. Put it to the indicator, for high beam. The horn is a very light green. After K2 there was not much changed on the wiring.
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: new harness now bike wont run just back fires 76 cb750

globalfastener
ok...ill check it out when i get to the shop.  thanks for the info
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
i have a black, green and light blue wire coming from the light panel.  i dont see these on the diagram.  any idea what they are for?

it turns out my wires and the points were crossed..thanks for the help on that
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
nevermind   stupid questions
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Re: new harness now bike wont run just back fires 76 cb750

Piute
In reply to this post by globalfastener
   ..o.k. global you said "i should be looking at the k6 diagram right?  it shows the horn is green "
     .........Myself on my "77",Went through all my wires and just had 2 switched plugs...
      ........ witch I did (bone-head)but found yel N blu from points.....
  Now looking at K6 (wire diag.)your right the horn is (also)green ,from horn button A single wire plug to the horn it-self,
                 There's also A Grn.they all come together for ground to Frame or Alternator.
  The light blue is right signal
  The orange is left
  The black is a power,not knowing for sure were your looking
   does splits off 3 ways plug from stop switch But powers turn buzzer and oil pressure and neutrals,
    AND.
   ,.that goes through out your electrical
 Black and white are your coils.
     THIS I'M TAKING STRAIGHT FROM THE MANUEL...Piute...
                            1977 CB750 F2 Super Sport
<LET THOSE WHO RIDE DECIDE><RIDE TO LIVE-LIVE FOR JESUS> 
Native American from central Cal,  Kickstand UP in S.W.Missouri,
                                       
 
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Re: new harness now bike wont run just back fires 76 cb750

TOOLS1
Administrator
The wire from the switch to the horn is light green. The grounds are dark green.
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: new harness now bike wont run just back fires 76 cb750

globalfastener
ok..i am going nuts

i hooked everything up according to the diagram.  this is what i have left over from the main harness

dark green 4-way
black and red
black 4-way
solid brown

and then from the left switch i have a brown and blue

also, my gauge lights, turn signals and headlight does not work.

i can start moving wires around and get the gauge lights and headlight to work, but i was trying to put it all back the right way

any thoughts?
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
the red and white wire from the solenoid is heating up pretty bad too
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
how may fuses should there be in the box?
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Re: new harness now bike wont run just back fires 76 cb750

Piute
In reply to this post by globalfastener
   I'm just going by the book :

    dark green 4-way..Not sure what you mean 2 in 2 out ?
   
    black and red..goes from starter switch to the fuse block (7amp)no joints (tye ins)come out of fuse block
    brn & red
   
    black 4-way,Not sure what you mean 2 in 2 out ?
   
    solid brown is tail light from ingnition to fuse block(5amp.) brn in brn out



............Theres only one more fuse in the block and thats your main (15amp.)red wire in & out
                            1977 CB750 F2 Super Sport
<LET THOSE WHO RIDE DECIDE><RIDE TO LIVE-LIVE FOR JESUS> 
Native American from central Cal,  Kickstand UP in S.W.Missouri,
                                       
 
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
i think one of the green is 1 in 4 out
the other one could be 2in 2 out

everything works on the bike except the brake lights, turn signals and  headlight.

does this bike have a turn signal buzzer?

i am starting to think i am missing a few components.  should every wire have a home or will there be some open connection.
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Re: new harness now bike wont run just back fires 76 cb750

Piute
..".i think one of the green is 1 in 4 out.".
Is it possible that this has one(grn)plugged in between 2 grns and theres 2 grn on other end of this one connector:o.k. were the single green comes in beside it 1 goes to R front turn signal .,.other to high beam indicator,o.k. on other side(straight over) of connector the grn wire is going to tach bulbs(2) the other to headlight..

 "the other one could be 2in 2 out"lost here.

everything works on the bike except the brake lights, turn signals and  headlight.

 "does this bike have a turn signal buzzer?" YES.(blk wire and a brn & blu wire,..

 "i am starting to think i am missing a few components.  should every wire have a home or will there be some open connection."
........there is a single brown that shows no connection one leg off a "T" brn.is brown out fuse block "Ts" off one to no connection and the other to tail light
                            1977 CB750 F2 Super Sport
<LET THOSE WHO RIDE DECIDE><RIDE TO LIVE-LIVE FOR JESUS> 
Native American from central Cal,  Kickstand UP in S.W.Missouri,
                                       
 
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
ill hit it again tomorrow.  

did i mention i hate electrical.
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Re: new harness now bike wont run just back fires 76 cb750

globalfastener
what wiring diagram are you referring to?  i have been using the k6 diagram, but the k3-7 diagram looks more like what i am dealing with now that i look a little closer
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Re: new harness now bike wont run just back fires 76 cb750

TOOLS1
Administrator
In reply to this post by globalfastener
The green, and black wires should be filled with wires. Black is hot, green is ground.
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: new harness now bike wont run just back fires 76 cb750

globalfastener
TOOLS1 wrote
The green, and black wires should be filled with wires. Black is hot, green is ground.
TOOLS
i definitely dont have enough wires to fill the green and black.  

it looks like the solid brown and the black/red wires are accounted for according to Piute n Judose
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