• The software has been updated. Message Travis if you find any issues.

Where to Start-1979 750f Super Sport? Carb/Compression or both?

you're welcome! if you have any uncertainty, post some pictures of the plugs or anything you find. pictures are worth 1,000 words.
 
A somewhat unrealted question:
I was able to ride this bike 5-6 miles for the first time since I got it.
Overall ran well not great but well.
Never ridden a Honda CB anything before let alone a 750F (wasn't running when I bought it)
Definitely not a Road King
Seemed very torquey in every gear, I assume thats normal?
 
Ok here are the pictures of the plugs.
Its starting and idling great.
But bogs down when I get on the throttle
I can hold it 80% open and eventually it seems it comes to life but by then I have run out of road in my subdivision so not sure
anyway I did check the boots on the airbox side and they were not sealed very good and did fix that, not sure it had anything to do with it.
Also confirmed the jetting is 68 and 88
 

Attachments

  • IMG_4444.jpg
    IMG_4444.jpg
    326.5 KB · Views: 17
I also just did a compression test and all 4 cylinders are setting at 150 psi
I was able a couple of times to add choke when revving it and got it to go to 7K but it soon bogged back down.
 
I also just did a compression test and all 4 cylinders are setting at 150 psi
I was able a couple of times to add choke when revving it and got it to go to 7K but it soon bogged back down.
Yes as Brett says, it sounds like it is running lean. Also have you got the floats adjusted properly?
 
Wow. Those don't look lean, with the obvious exception of the one that looks like it isn't getting fuel at all. Which you need to address.
Those are fairly dark; I wonder if those are actually rich! I would fix the fuel problem on that one carb first. Then see how she does.
 
I have pulled the carbs again and extracted the slow jet, I thought it would be clogged but it seemed to be clean.
That was the only jet left to clean.
Bought new slow jets, any tip to pressing it back in without dammaging them?

So I get fuel to the bowl, and all jets are clean, I can also tell the accelerator pump is spraying into each carb.
What is left to check with #3?
 
I have pulled the carbs again and extracted the slow jet, I thought it would be clogged but it seemed to be clean.
That was the only jet left to clean.
Bought new slow jets, any tip to pressing it back in without dammaging them?

So I get fuel to the bowl, and all jets are clean, I can also tell the accelerator pump is spraying into each carb.
What is left to check with #3?
Air Cutoff Valve (ACV). I think when they go bad, it will cause a rich condition.
Note, I didn't read back through this thread to see if that's been done.
 
Back
Top