99 yz400f hard to start

26 replies to this topic
  • brandonvick83

Posted October 27, 2010 - 02:31 PM


what kind of bigger problems? anyway got the pilot out have to wait till tuesday to get the 45

  • gscx

Posted October 27, 2010 - 02:44 PM


So the threads are fine for the pilot jet? I thought you said it just spun?

  • grayracer513

Posted October 27, 2010 - 03:29 PM


Your pilot jet won't come out of the carb in a normal manner, it's 3 sizes bigger than stock, and the bike acts lean. It sounds like there is something very wrong with the carb, which is not unheard of for a 400, and a used 450 carb may be your best bet.

The best replacements are the '05 and later YZ450 carbs. They complicate things a bit because they use a cable operated hot start, which means you need the lever, etc. A carb from a 426 has a hot start knob on the carb, but they are harder to find in good condition. Either one is very close to being a bolt-on mod.

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  • brandonvick83

Posted October 27, 2010 - 08:10 PM


I took it to the shop and they were able to push it out from the other side they said it was just in there tight and the threads look fine they also suggested I be running the 45 in this area so i'll try that and go from there...can you get a newer 450 carb for a reasonable price?

  • brandonvick83

Posted November 04, 2010 - 11:06 AM


ok so I got the 45 jet and I cant get it started

  • brandonvick83

Posted November 07, 2010 - 10:56 AM


Im open to check or try anything any suggestions ideas?

  • brandonvick83

Posted November 07, 2010 - 11:37 AM


also I found a 09 yz450f 39mm keihin carb on ebay for 200 will this one work?

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