99 400F carburation

2 replies to this topic
  • c-man

Posted August 08, 2002 - 05:53 AM


I know this may be a worn out topic for some long-standing TT members, but please lend me any knowledge you have. I have had my 99 400F for 2 years and I love it. Would never go back to a 2-stroke. My father liked mine so much that he went out and bought a 2001 holdover. I notice that my bike idles a lot rougher than his does, and even somewhat rougher than other 98 & 99's that I have seen. It is annoying to have to rev it occasionally at idle to keep it going, or adjust the idle screw up, and then have it race at idle after you run it hard and slow down. Any input you may have will be appreciated! Thanks boys. :)

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  • MDK

Posted August 08, 2002 - 10:42 AM


Take a look at ...


it comes with a 180 main jet, and I forget the other jetting sizes, but I really like what it did for my 99 yzf400. It got rid of that poping sound when deaccelerating, and starts with one kick every time (almost :-))

[ August 08, 2002: Message edited by: MDK ]

  • Shawn_Mc

Posted August 08, 2002 - 01:52 PM


C-man, you have an intake leak. Or your jetting is way off on the pilot circuit or maybe you need to clean the carb or maybe........this could go on for hours.

Clean the carb. first then reset the pilot screw at 1 1/2 turns out and start from there. And make sure you dont have an intake leak somewhere between the carb and the cylinder head.

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