yz400 oil problem

5 replies to this topic
  • burto644

Posted August 29, 2006 - 02:37 AM


hey guys, i own a 98 yz400 and i did an oil change and was out riding on sunday and i noticed oil was coming out of one of my breather hoses that connect to the head of my motor. just wondering if anyone has an idea of why that might be doing that and if it is serious. cheers sam

  • SRT426

Posted August 29, 2006 - 02:40 AM


Did you overfill it?

  • bentru

Posted August 29, 2006 - 07:06 AM


Yea, I had the same thing happened to me. I made the mistake of checking the oil after the bike had been off for a while. It didn't even show on the dip stick. So I kept adding. Once it finally started showing on the dip stick, I went for a ride and it spewed out oil until it was down to the proper level. It was way too full. Now I know to only check it about one minute after it has been turned off (just like the manual says.)

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  • grayracer513

Posted August 29, 2006 - 08:01 AM


A certain (very small) amount of oil dripping from the breather is normal. Usually, this will be a few drops after a hard run, or on the garage floor. More than that can mean too much oil in the system or an excessive amount of combustion blow by due to tired rings.

  • burto644

Posted August 29, 2006 - 01:33 PM


would my bike be blowing smoke if my rings tired?

  • grayracer513

Posted August 29, 2006 - 01:53 PM


Not necessarily. The compression rings may leak while the oil rings are still in good shape.

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