New To Yz400f

6 replies to this topic

Posted February 11, 2006 - 03:12 PM


Just got a 99 yz400f. The guy i bought it from had a hell of a time starting it but it eventually fired. The outside temp was in the low 50's. I tried to start it today without any positive results. What gives with this ? Is this normal? The guy i bought it from said they were hard to start in cold weather.
Any help would be very cool.thanks

  • TT66

Posted February 11, 2006 - 03:27 PM


Good deal we can ride together again :thumbsup:

  • heinzee

Posted February 11, 2006 - 03:37 PM


Congrats. Just got a 98 two weeks ago. These bikes are hard to start all the time if you don't do it a certain way. Mine starts first or second kick every time. This is what I do. First don't touch the throttle at all. Put your hand on the master cylinder. Pull the decompression lever in and kick it through a couple of time. On the third down kick stop where you fell it getting hard to kick go about an inch past that then let the kick start level return to the top. Let the decompression lever out and kick it like you mean it. This works every time for me hope it helps. Heres a link that will help also.


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Posted February 11, 2006 - 03:42 PM


thanks for the advice. i will try that tommorow

  • bryan103

Posted February 11, 2006 - 04:27 PM


i just got a 98 to, it was hard to start at first,put in the pro circuit air fuel longer needle and the nology plug wire,helped alot,i just get the motor in the sweet spot,hold the throttle open just a crack and it fires on second kick cold or not,but it wont idle so its in shop, hope nothing serius

  • YZ400FPower

Posted February 11, 2006 - 04:36 PM

#6 just need to learn the starting procedure.its a pain but thats how it is........


  • PumpkinHumper

Posted February 11, 2006 - 04:56 PM


Another thing is dont start the bike just to hear it run. If your not gonna ride it dont start it. It kills plugs doing this. Yes sometimes you do have to start them when your working on them but that is the only time I will start it and not ride it. Even if its just up and down the driveway to clean it out it will help next time you go to start it.

And yes they can be stubborn to start in cold weather but 50 deg shouldn't make it that hard to start. I get mine fired up in 20 deg weather around here with just a little jetting work to compinsate.

For cold starting pull the choke out. Give it like 2-3 twists of the throttle. As others have said slowly kick it thru till the piston hits TDC, it will get hard. Pull the compression release and kick it about 1" farther. Release the compression release and bring the starter back to the top and kick it like you mean it. If it fires and stalls give it one more twist and kick again. Just make sure you dont twist that throttle too much. Every time you twist it it shoots fuel into the cylinder. Make sure you kick it over like 5x between kicks to clear the fuel outta the cylinder.

You kinda just have to get the feel for what these bikes need to fire. They can be a little finiky at times. Youl figure it out in time just be patient and get a few extra plugs cause you are gonna need them.

You might also want to try an irridum plug. It will help starting a lot.

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