carburetors - Part II

CB750 taking the carburetors off with ratchet bike tie down

I took the carburetors off again. This time, I decided to work on the needles area. I took off the back plate from the assembly, but did not undo the choke connection. Once that's done, I could hand twist to unscrew the top "ring thing". Once they are off, I can clean the needles. I also cleaned all the jets again. One of the slow jet was already clogged with a piece of dirt. I then looked into the drain plug. They were COMPLETELY clogged up with gunk. I let it soak in gumout, but no avail. I had to manually clean them.

CB750 needle clip on fourth slot

I had noticed that the carbs are 657A model. But it has been rejetted with 120 main jet, since it has the four-in-one exhaust.

CB750 Carburetor Settings by type

Now they are back on. It runs better. But it is still increasing the RPM as soon as I disengage the choke. It must have some vacuum leak somewhere.

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