98 yzf 400

4 replies to this topic
  • djp1998

Posted February 11, 2009 - 08:32 PM


98 yzf400,bike is hard to start you half to prime with a little fuel then pull choke hold compression release kick 5 times let go of release then kick from TDC when it does fire its dumping oil into header ,i bought this bike a week ago it sat for 2 years so carb had got sticky inside cleaned it out and put new spark plug in it but it just wont stay running any ideas thanks

  • Dano426

Posted February 12, 2009 - 08:18 AM


A hard starting YZF is a sign of two things
1. Dirty Carb - Make sure you are cleaning jets with cleaner and air compressor.
2. Tight valve clearance. Check and reshim if necessary

Oil dumping into the head is another issue
Sounds like you need a new piston and rings.
Get a compression tester and see where your compression is at.

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  • grayracer513

Posted February 12, 2009 - 09:33 AM


How do we know it's "dumping oil into the header"?

  • DFuller

Posted February 15, 2009 - 06:14 AM


lack of compression on any, any motor cycle or not can lead to hard starting and oil in exaust.

  • DFuller

Posted February 15, 2009 - 06:16 AM


if your compression is due to bad piston and/or rings

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