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Jet part numbers

Discussion in 'Technical and Troubleshooting Torque' started by Dylan05, May 21, 2012.

  1. This is probably for the CBR 400 NC 23 owners but I just need to clarify the type of jet that go into a VG04B carby before I buy parts. I have pulled the current Keihin pilot and main out measured them and I think the part numbers are N424-21 (40 pilot jet) and 99101-393 (105 main jet) are these the correct jets for this model carby? The haynes manual just tells you the jet sizes not the specific part numbers. The bike is a track bike with an aftermarket can on it. Should I also being going up the next size in jets?.


  2. I don't think you are going to get an answer to something that model specific in here.

    As to whether you need to change jets, you really need to asses how the bike is performing. Read up on plug chops and do some research in to how a bike behaves when it is running either rich or lean.
  3. I could only hope.
    Mainly looking at going bigger in the jets as its a track bike and spends more time WOT than anything down low, runs fine though
  4. Just guessing which way to go will NOT provide decent results.

    1] Go to Dynowerks, PTR Racing or a TRUSTWORTHY mechanic that has a dyno and exhaust gas analyser...tune the thing properly to arrive at a base setting..

    then you can vary the jetting a little one way or the other to suit individual track or weather conditions...
  5. Jet part numbers will be in your service/parts manual for the bike if you want to get them from Honda, otherwise work out which specific type of Keihin jets they are & get them from a dealer.

    Mick Hone have been good in the past, they are the only ones who stock the push in Mikuni jets that my bike uses, they should have most things on hand.
  6. I was thinking of doing it the old fashioned way, changing jets ride the bike and so on, should just book in a dyno.
  7. Nah nothing in the manuals, just the type of carby, rang sho and go in adelaide and they have the jets just wanting to be 100% before I order them, will check out mick hone first before I order them. thanks
  8. Thanks MV got them off Mick and cheaper too.
  9. Good to hear. (y)