Date: 27-04-24  Time: 09:36 am
« previous next »
Pages: [1]

Author Topic: Not sure if my carbs have been jetted  (Read 436 times)

Texan67

  • Cager in Training
  • Posts: 11
    • Main bike:
      FZS 1000 Gen1
    • View Profile
Not sure if my carbs have been jetted
« on: 27 January 2024, 08:58:32 pm »
I bought my '03 from the 2nd owner. He actually bought it from a shop. The first unknown owner installed a Yosh slip on. I've put almost 20,000 miles on the bike and it has always run perfect. Fires up instantly, idles perfect, butter smooth all the way up to redline. No popping or anything. Probably the best running bike I've ever owned.


Does it sound like it was jetted for the pipe? I ask because I'm going to call and see if Dale at Holeshot still has a set of headers for it and I'm not sure if I'm going to have to address the carbs. I know he runs a stage one jet kit with slip ons and full exhausts so if mine is already jetted I should be good to go. And yes it has the stock airbox.


What do yall think?
Logged

unfazed

  • GP Hero
  • ******
  • Posts: 5,324
  • Never ride faster than your guardian angel can fly
    • Main bike:
      FZS600 02-03
    • - FZS1000 05-06, Serow 2000
    • View Profile
Re: Not sure if my carbs have been jetted
« Reply #1 on: 28 January 2024, 02:15:25 am »
Only easy way to find  out is take off the float bowl and check the size of the main jet. The left side float bowl can be removed with the carbs on the bike, it's just a bit fiddly.Standard main jet on that carb is 132.5
Logged

Falcon 269

  • GP Hero
  • ******
  • Posts: 5,899
    • Main bike:
      FZS 1000 Gen1
    • - Yamaha R1 1999
    • View Profile
Re: Not sure if my carbs have been jetted
« Reply #2 on: 30 January 2024, 09:36:36 am »
There is another way, although not quite as iron-clad as checking the main jet size.

Remove one of the carb tops and check out the throttle slide spring and the needle.

If the slide spring has been cut - it will be pretty obvious if you compare the ends of the spring - there's a good chance that it's been re-jetted.

Now, check the needle.  If it has SD-130 stamped on it, it's stock and it will have a straight-line taper. 

If it's not stamped SD-130 (poss SD-110, there are two needle part numbers, one type for the inner two carbs, the other type on the outers), it will be an aftermarket needle. 

If you're unlucky, it will be Dynojet needles (which are same taper as stock, just mounted higher) but odds are in the USA that you will have one of Ivan's kits installed.  His needles have 5 very subtle changes in the taper along the length of the needle.

Since your bike is running perfectly, my money is on yours having Ivan's Inside, and because the airbox is stock, I suspect it's his Slip-On kit.

This should work fine with a set of Holeshot headers but not sure that Dale would agree ... ;)
Logged
Pages: [1]
« previous next »