04 Yz450F stalling when giving throttle after a coast..

Any ideas why my 04 yz450f would be stalling at a blip of the throttle from a slow speed....no popping or nothing on accel or anything....just if i pull in the cluth after coast down a slow trail and hit the throttle it will die...i was wonder if anyone else had this problem...but overall this bike is awesome...thank everyone :thumbsup:

Hey I have this problem too sometimes. I'll just be coasting and go to do a burn out or somethin and it will just die. My dad is really good with bikes and engines and says that it is too rich, or that the accelerator pump is adjusted wrong. Mine does not do it very often and when it does its only after the engine has dropped down to the slow idle. So I am not too worried about it, but if it ever quits in a higher rpm then I'll definately have to fix it, because thats the last thing you want to happen on the face of a triple :awww::thumbsup::lol:

there is a laundry list of situtations that could be occuring, but what comes to mind first for me is..

- make sure the bike is warmed up thoroughly before trying this trick.

- check idle setting, too low/high can stall it if you feed a handful of throttle then chop it quick.

- fuel screw - adjusted properly?

..thats all I can think of, hopefully you'll get some more info.

all of what oc said was correct. make sure that those are all adjusted first. i have also had this problem. yet what you need is a flywheel weight. for some reason the flywheel isnt heavy enough and when it gets down to low coast or low idle it kills the bike. i havent bought one yet but i am gonna get one soon. go down to your local yamaha dealer and ask them what size weight you will need. it will be something like 6oz,8oz,etc.hope that solves your problem.

-Carb/Air filter need a good cleaning?

-Spark plug in good shape/gapped correctly?

I always start with these when trying to find a problem before starting to change adjustments/jets.

i have the same problem. i ordered the zip ty fuel screw and once i have it. i'll get busy.

first, make sure the fuel screw is as close to perfect as possible. i have heard going to a smaller pilot (like 40) helps. if not, try a size larger. lastly you can back off the timing cam on the accel pump. take the cover off the side of the carb and back the screw off slightly (liker 1/4 turn). this adjustment makes a big diff. you will notice less initial hit out of 1/4 turn. however, if the pilot sizing is the problem backing off the accel. pump isn't the best solution.

good luck,

vet28 :thumbsup:

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