1980 cb 750 tuning

[750_cafe]

My 1980 cb750f super-sport has been a heck of a project, I have done everything needed cosmetically, and just finished the wiring not long ago, now all that’s needed is a tune. The bike tends to start, but can not stay running. I have messed with the carburetors enough to know it could be the jetting. I’ve had the bike running for tops 3 minutes at a time before it subsequently bogged down.
Note: choke needs to be on full for it to even turn over and stay running, sounds like it’s lean but wanted to hear from people with experience! Let me know what you think!

 

[Motogrady]

First thing I’d do is pull the fuel line where it connects to the carbs, stick the end in a small can, turn the petcock on and make sure you have a good, steady stream of petrol feeding the carbs.

 

[Bo82CB]

This is not related to your bike running but when you get that bike running and it is running while standing still, make sure to have some fans blowing at that cylinder head...

 

[brettp]

Are your coils hooked up to the correct cylinders? I commented on your other post.

I need the choke on at first start, even in Florida.

 

[750_cafe]

Are your coils hooked up to the correct cylinders? I commented on your other post.

I need the choke on at first start, even in Florida.

I have it set up like this

Coil 1 to cylinder 1
Coil 2 to cylinder 3
Coil 3 to cylinder 2
Coil 4 to cylinder 4

Hey brettp! Luckily as I was rebuilding this bike the coil packs and plugs were labeled with number coil, and number cylinder. Although that’s what they say I’m always gonna take it with a grain of salt, any idea what this could be?

First thing I’d do is pull the fuel line where it connects to the carbs, stick the end in a small can, turn the petcock on and make sure you have a good, steady stream of petrol feeding the carbs

Thank you for the advice motogrady!!

 

[brettp]

Your coils are wrong based on your description.

 

[750_cafe]

Your coils are wrong based on your description.

What would the order be in that case?

 

[brettp]

Left to right, let's label the coil connections A to D. We will keep the cylinders 1 to 4.
Connection: A B C D
Cylinder: 1 4 2 3

 

[750_cafe]

Left to right, let's label the coil connections A to D. We will keep the cylinders 1 to 4.
Connection: A B C D
Cylinder: 1 4 2 3

Thank you! I will be trying this tonight!!