Topic: First motorcycle! 1977 cb550f jets discovered in 069a carbs

[JDillon]

This is my first post on the sohc forum- which has already helped me a ton in deciding which bike to purchase and how to go about starting my first project!
So I picked up the 77’ 550f with 6k original miles, started great but it had pods on it so was running decent, but LEAN!
 My first step was to hunt down a nos air filter setup, which Ive acquired. Then cleaned carbs while I was do air filter change over- I found this setup- 3 original looking jets stamped 98 on bottom and this “75” stamped one on carb number 2. Has anyone seen a jet that looks like this?

Ill post image of “75” and “98”.

I can’t find any images of the original press jets online, and I have to assume it’s actually a 75 and im gonna replace all 4 to keep things consistent...

[flatlander]

98 is correct for the stock setup. jetsrus.com sells the original keihin jets. everything else won't be the same.
without knowing what the PO did it's impossible to say why there's a 75 in there and if it's still 75 and not drilled out? i'd just replace it with a keihin 98 and be done with it.

[flatlander]

did you have any luck with your jets?

[JDillon]

So I ended up replacing the four jets with  new ones and it ran great with stock air setup and new 98’s. Now i have a new issue with syncing that i will need to make a new post about- loose adjusting arm on carb 1.. it wont hold adjustments properly.

[flatlander]

ok, good to hear the jets worked out for you. will keep my eyes open for your syncing post