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Discussion Starter #1
Did a search for a starting trouble shoot checklist and have not found one on here so I'm starting a thread. If you know the link to such threads, please post here.

My 80' cb750c is not starting unless I hold the starter button and roll the throttle and if it does start running, it cuts out when I release the starter to grip the throttle.

I would like everyone to help link to trouble shooting checklists.

My limited knowledge so far leads me towards the following:

- drain fuel and start with 2 gallons of fresh fuel (fuel line is clear, I added an inline filter and I added sea foam to premium fuel)
- check oil and change (I changed the oil and filter and cleaned the oil pan)
- replace spark plugs (replaced with NGK's)

- remove plug caps to check for spark (this is my next step)
- spark does not guarantee that the coils are functioning properly (HOW CAN I TEST THE COILS without replacing them?)
- spray starter fluid in air intake (If it cranks, vacuum intake boots are fine)
- check timing settings
- inspect carbs (I have cleaned mine fully)


ANYthing else I have left out????
 

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Discussion Starter #2
Is anyone using these lit spark plug caps? (I can not add the full url until I post 2 more topics as a newbie)

ebay 2FastMoto-Lighted-Straight-Spark-Plug-Cap-RED-Look-Like-Neon-PAIR-Honda-NEW-/191426371641?fits=Year%3A1980%7CMake%3AHonda%7CModel%3ACB750C%7CSubmodel%3ACustom&hash=item2c91e6a039:g:KrAAAOSwnDxUdO~E&vxp=mtr

I would like to get them but not if they do not perform as well as a set of NGK's.

THOUGHTS?
 

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Starting system must be the problem if you have to hold the button in to keep the motor running...there must be a direct short of the ignition circuit when the button is released.
 

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Starting system must be the problem if you have to hold the button in to keep the motor running...there must be a direct short of the ignition circuit when the button is released.
That's an interesting take.
I didn't read his description that way at all.

Where to start chasing this problem depends a lot of whether or not it has ever started good while in his possession.

It could just be a matter of not using the choke (enough) and the idle stop being set too low.
Not having the air filter in place........or a high flow filter can make the problem worse.
 

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is not starting unless I hold the starter button and roll the throttle and if it does start running, it cuts out when I release the starter to grip the throttle.

I saw those two points and figured it runs for as long as the starter button is pressed once released it dies...
 

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is not starting unless I hold the starter button and roll the throttle and if it does start running, it cuts out when I release the starter to grip the throttle.

I saw those two points and figured it runs for as long as the starter button is pressed once released it dies...
That might very well be true.
If so, it would be a rather unusual situation.
 

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Did a search for a starting trouble shoot checklist and have not found one on here so I'm starting a thread. If you know the link to such threads, please post here.

My 80' cb750c is not starting unless I hold the starter button and roll the throttle and if it does start running, it cuts out when I release the starter to grip the throttle.

I would like everyone to help link to trouble shooting checklists.

My limited knowledge so far leads me towards the following:

  • drain fuel and start with 2 gallons of fresh fuel (fuel line is clear, I added an inline filter and I added sea foam to premium fuel)
  • check oil and change (I changed the oil and filter and cleaned the oil pan)
  • replace spark plugs (replaced with NGK's)
  • remove plug caps to check for spark (this is my next step)
  • spark does not guarantee that the coils are functioning properly (HOW CAN I TEST THE COILS without replacing them?)
  • spray starter fluid in air intake (If it cranks, vacuum intake boots are fine)
  • check timing settings
  • inspect carbs (I have cleaned mine fully)
ANYthing else I have left out????
Thanks for sharing this information it helps a lot while bike not started
 
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