450 re-start after stalling


4 replies to this topic
  • smokin529

Posted January 17, 2005 - 04:05 PM

#1

I have an '04 yz 450 that starts cold or hot with one or two kicks, but if it stalls it can take twenty kicks to get it going. I have a Zip-Ty fuel screw and an FMF power bomb header, that is all. Anyone else had this problem? My hunch is jetting, but I am not positive.

  • mxmhero

Posted January 17, 2005 - 04:23 PM

#2

Do u mean its hard to start right after u get it started and it stalls, Or is it hard to start if u stall it while riding?, If it stalls while riding most 4 strokes are hard to start once they get hot from riding.

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  • grayracer513

Posted January 17, 2005 - 07:21 PM

#3

If they stall, and even more so when the engine dies while on its side, they are prone to being flooded. Since that's a condition of being too rich, what you need is more air than fuel. Open and hold (don't twist or pump it) the throttle between 1/2 to 3/4 open, more or less, hold the hot start open and kick. With the throttle farther open there will not be enough vacuum while cranking to draw fuel through the idle circuit, and the bike will inhale almost nothing but air. This will balance out the excess fuel and help it fire. If it hasn't lit in 3 kicks try coming down to 1/4 throttle without the hot start. Every situation is a little different, as is every bike, but this usually works for me, even on other guys' four strokes. Experiment with it. :cry:

  • sirthumpalot

Posted January 17, 2005 - 07:34 PM

#4

Use the hot start! If you're not using the hot start, then start using it, it's a must! If you are using it, then what grayracer says is true; just beware that if the bike were ever to kick back during starting, it is more likely to do it when the throttle is open than when the throttle is closed. The old 4-strokes were horrifying when they kicked back, the new ones almost never kick back, but if it does it will get your attention.

  • smokin529

Posted January 17, 2005 - 08:37 PM

#5

I definitly use the hot start button. This is my third YZF. It only does this when it is hot and I stall it. The '98 400 and '02 426 both were mules to start if a guy didn't know the drill. But on both those bikes when I stalled them I'd use the compression release and kick it three or four times to clean it out then find TDC go a hair past and they'd both light right up. Can't do that with the new 450. I'll try holding the throttle open a bit for sure.





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