VT750 idles but dies when I crack the throttle

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  Nicky Wee

  2/2/26, 1:51 PM

  Having some idle issues with 99' shadow VT750.  I installed the performance kit with stacks and pipes and everything went together easily.  Bike starts up and will idle without choke fine but as soon as you crack the throttle it dies. Air/fuel screws I started at 2 turns out and took them to 3.5 but same issue. 
  
  

  I used the smallest jets in the kit to start (idle and main) and used one spacer shim on each needle.  Is it just way too lean?  What should I try? 

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  Erotic Jesus New Member

  4/30/26, 6:13 AM

  I would  make sure there are no intake leaks. 9 times out of 10 it's an intake leak.
  Have it idle and spray the intake manifold with wd40. If the ilde changes it's an intake leak.
  Check your plugs, they'll tell you exactly what's happening in the combustion chamber.
  If it's steady at idle, see if you can roll to open throttle. If it stumbles as you roll it might be lean.
  Try rejetting at that point.
  
  
  

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  TJ Admin Staff member

  5/5/26, 12:11 PM

  @Nicky Wee YOU NEED TO TUNE! LOL the kit is not just a slap it in and go! every bike needs something different so thats why we incluide multiple jet sizes! 
  
  herres a link to all the tuning info you need . Until youve gone through this info you will likely be throwing shit at a wall hoping something sticks LOL 
  
  https://shoptjbc.com/community/brutalforums/topic/176621/tuning-your-carbureted-honda-shadow-everything-you-need-to-know

  DO FUN SHIT!
  Check the FAQ's here for tons of tuning info and more!! - t.ly/MA6r6

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