Carb Question

[Kidfastidius]

I know it’s a long shot but figured I’d try….

I’m in the process of restoring my father in law’s 1981 Cb750 Nighthawk and everything on this is a first for me.

I’m in the final steps of the carb rebuild, have a rebuild manual and shop manual and yet at the end of the build I have two washer left that I can’t seem to place anywhere? Figured maybe someone that does this often could give me a few places to look.

I’ll definitely be taking a picture of every single bolt washer going forward

 

[93trident]

Have a look on CMSNL.com they have pages of Nighthawk years and spares to look at.

 

[Wfokid]

Have a look on CMSNL.com they have pages of Nighthawk years and spares to look at.

Hey what’s happening I have a 1979 750f super sport I love the bike I can’t make the carbs work it just Doesn’t have any power and falls flat it has compression I hate the carbs am I stuck with them or can I go single carbs in line without all the sinking and all that BS

 

[93trident]

Hey what’s happening I have a 1979 750f super sport I love the bike I can’t make the carbs work it just Doesn’t have any power and falls flat it has compression I hate the carbs am I stuck with them or can I go single carbs in line without all the sinking and all that BS

The carbs have very small passage ways especially the pilot jets. You need to remove those and clean the passage ways with a fine guitar string. I think I got a pack of fine e strings. Worked on mine after a few sessions in the sonic cleaner. My pilots are push in not screw in so you need to make a small puller out of a bolt, nut and washer if yours are push in
You need to use a small tap first to thread the top of jet. Its easy and makes life easier you want to change in future after cleaning. I had carbs in bits today and couldn't find those wee parts in your pics. That's if they are the same CV carbs as my 81 CB750K. I think yours are the same. Dunno if any of this helps you.

 

[cb forever]

I have replaced the kei-hins with mikuni's. World of difference. It takes a little bit of tuning at first, but jets are cheap and I order mine from Amazon. Once you have them dialed in your done tuning. MIkuni has a four into two kit that simplifies it. They supply the new cable as well. If you're a purist and want to stay stock for the sake of it being stock, that's fine. I personally build my bikes to ride, and not for show. You won't regret going with mikuni's. It's hard to explain to someone who hasn't experienced it for themselves, but the power gains, as well as the overall rideability and ease of adjustments more than offsets the initial cost.

 

[Old_Crow]

Hey what’s happening I have a 1979 750f super sport I love the bike I can’t make the carbs work it just Doesn’t have any power and falls flat it has compression I hate the carbs am I stuck with them or can I go single carbs in line without all the sinking and all that BS

Are you running pod filters or the stock air box. It makes a difference with the CV carbs.

 

[Oscar Meyer]

These carbs are not difficult. The problem is guys pull these carbs apart without really understanding how a carburetor works. They pull them apart and clean a few pieces and then assemble them wrong and then they curse them and complain when they don't work. I have seen guys on other forums saying "I have disassembled and cleaned these carbs 3 times and they still don't work right". Well they should have stopped after the first time because it only takes 1 time to do the job, not 3 times or more. The other thing guys do wrong is buy cheap kits off places like Amazon. There are hundreds of threads on these sites all for the same thing. It is the person doing the work, not the carbs that are the problem. This isn't just a Honda CB problem because if you go onto a Kawasaki or Suzuki or Yamaha site and guys are dealing with multiple carbs, they are bitching and complaining about their carbs too because they just don't understand how they work.

 

[Old_Crow]

These carbs are not difficult. The problem is guys pull these carbs apart without really understanding how a carburetor works. They pull them apart and clean a few pieces and then assemble them wrong and then they curse them and complain when they don't work. I have seen guys on other forums saying "I have disassembled and cleaned these carbs 3 times and they still don't work right". Well they should have stopped after the first time because it only takes 1 time to do the job, not 3 times or more. The other thing guys do wrong is buy cheap kits off places like Amazon. There are hundreds of threads on these sites all for the same thing. It is the person doing the work, not the carbs that are the problem. This isn't just a Honda CB problem because if you go onto a Kawasaki or Suzuki or Yamaha site and guys are dealing with multiple carbs, they are bitching and complaining about their carbs too because they just don't understand how they work.

It extends to the single CV setups on Harley's too. S&S made a frigging mint off replacement carbs for the guys who hated the CV's they didn't understand.