my new yz400F

5 replies to this topic
  • CRF150Joe

Posted January 08, 2007 - 05:24 PM


Ok guys so i was on ebay and there was this 400F not in that bad of shape but his reserve was 360 and i offered him 400 and he took it so i got it today and its not that bad but it doesnt run. I was told it has a new top end but it doesnt have enough compression to start it like i can use my hand to push the kickstarter down. I have no idea what it can be. This is a project bike so its about to be torn down and fixed up and i want to get the motor working first so does anyone have any ideas or places to start?

  • tntmo

Posted January 08, 2007 - 09:31 PM


Maybe the compression release is sticking? Or the valves are way out of adjustment and don't close? That's what I would start with.

  • CRF150Joe

Posted January 09, 2007 - 02:36 PM


I thibnk thats what it is

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  • yamaha racing 230

Posted January 09, 2007 - 05:38 PM


lol dude i saw that 400f on ebay that looks like a good deal

  • BergArabia

Posted January 09, 2007 - 05:50 PM


Good luck.
you will have more clues when you open it up I guess..

  • CRF150Joe

Posted January 09, 2007 - 06:28 PM


well i opened her up and i did the basic reoiling everything and the little tricks i got a little more compression but not enough so start it for sure. So my guess is that piston rings or the valves by looking at it.

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