2 replies to this topic
  • yz400fmaniac

Posted May 28, 2016 - 08:08 AM


This is not A question it is an answer for people who are having the same problem I did.

hanging idle, throttle bog, backfireing: Ok hanging idle, first of all try turning your idle down that sometimes works... But not always next do a carb rebuild next buy aftermarket fuel screw (moose is the only i could find for my bike, the hole in the bowl where it goes in through will have to be drilled out it dosent hurt anything) ok if you put the screw at stock setting and it is still there 9/10 times on these bikes its not the pilot jet, Everwhere else people say to turn your fuel screw out more  :naughty:  I have found that this makes the hanging idle worse my bike likes 1 and 2/4 turns out, and check for air leaks and tighten all clamps on exaust. it will be gone now. :jawdrop: .


Throttle bog, I have done every mod... it is there and is going to stay there the only one that makes a noticable difference is the eddie mod it will not go away but it gets better if you dont want to spend 300+ on 450 carb just deal with it. http://www.thumperta...minate-the-bog/


Backfiring: pretty much common sense.. needs valve job this could also make your idle hang, "But my bike starts first or second kick so I dont need to do a valve job" YES YOU DO i thought the same thing and mine were way out of spec it helps everything i cant stress that enough, it makes the bike sound so much better and it just hits after you do the valve job... :thumbsup:  well thats it thats what I have learned about this bike in the 8 months i have had 

it it is a great bike and the motors are bullet proof and they run good when they want too, not when you want them to :goofy:


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  • 0bigsilver6

Posted May 28, 2016 - 08:19 PM


Don't mean to be rude, but there is a lot of mis information in here.

  • yz400fmaniac

Posted May 29, 2016 - 08:18 AM


You may think so but this is what worked for me and it is exactly what I did and the bike has never ran better

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