Topic: Carb Jet Purchase for 1975 Honda CB400f

[charliereid]

So i'm currently in the process of rebuilding the old carburetors on a neglected honda cb400f. It has AirPods on it, but it needs to be rejetted. From forum posts i've read it seems that the most common jets are 38 and 80 instead of the stock 40 and 75? correct me if i'm wrong. However, i can't find a place online to purchase the correct jets. The bike has the stock exhaust and stock jets. Any tips on where to get new jets? or possibly a kit that has many different sizes in case i need to tweak the jet sizing?

  Thanks,

  Charlie

[evinrude7]

try here.  http://www.jetsrus.com/  get keihin.

[zeffcat]

Heres the Jets R Us jets for a '75 CB400F.

[Bodi]

38 and 80 are pretty common with a less restrictive exhaust and pods. You will have lots of grief in the midrange with pods, tuning for them is a bear... reshaping the needles is the trick. A lot of plug chops or time on a dyno and innumerable removal/adjustment/replacement cycles of the carb stack.
No genuine Keihin jets are available between 80 and 90 now... so one either drills out 80s or tries the aftermarket ones (ugh.), if a jet in that range is needed. The numbers relate directly to the metering hole size though - a Keihin 80 jet is 0.8mm. Mikuni jet numbers are related to flow somehow and are not the hole size.