1999 YZ400

3 replies to this topic
  • Traskrider

Posted February 16, 2013 - 11:04 AM


Got a pretty good one on a trade, But after tearing into it I discovered that the over flow tube in the float bowl is crack causing it to leak out. After searching I cant find anywhere to buy just the float bowl for these carbs. Any fixes or any float bowls out there. Maybe I'm just missing it in my searches. Thank for any help !!

  • grayracer513

Posted February 16, 2013 - 02:00 PM


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  • twagner44

Posted March 18, 2013 - 04:09 PM


I had problems with the carb on my 99 400 that caused me to pull the rest of my hair out. The shop that I go to tried and tried but couldn't get it right either - finally told me to take it away and not bring it back. Parts were ridiculously expensive and not easy to find individually. One of the experts here on TT suggested that I try a carb from an 06 450 (there might have been a range of years, but that's the one I got), so I found one on eBay and slapped it on. The bike runs like a frickin charm. Just be sure you get one that comes with the cables since the hot-start is thumb operated on the newer carbs. It's pretty easy to find a bolt on lever for that too.

  • DGXR

Posted April 12, 2013 - 07:19 AM


The carburetor on my 1999 YZ400F was a rich source of nightmares for my mechanic and myself. Turns out that the problem was not our skills -- the carbs on these early 400s were not adequately developed before the bike was released. Search around and you will hear many people having carb problems with these bikes... external accelerator pump is not good, slide sticking and wearing out, etc etc it's just a flawed design that cannot be fixed, only band-aided until it starts acting up again. Anyway we finally decided to pull the trigger and replace the stock carburetor with a 2005 450F model (and pulling the trigger to finally kill that awful stock carb). I agree it's important to get the right cables to fit the updated carb to the older model bike, and the AP fuel shot is a bit fat since the carb is spec'd for a larger engine (sometimes it stumbles a bit if wacked open at low RPMs). Otherwise it starts easily hot or cold and runs great, a highly recommended upgrade.

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