03 yz450-Oil coming out of my camshaft exhaust?

2 replies to this topic
  • Pinstripe

Posted May 13, 2007 - 11:50 AM


I just went to fire up my 03 yz450 and it started smoking like crazy...It ended up there was oil on the exhaust causing the smoke, however the oil was spraying out of my cylinder head by the camshaft exhaust?( a vent on the upper right hand side of the head) onto the radiator then down to the exhaust pipe. I checked the oil level and was not missing any, fired it back up and rode it around a little bit and as I expected, the oil was still coming out. After it cooled down, I started it back up and put my finger over the camshaft exhaust and it quieted the engine up a little bit but continued to coat my finger in oil. I rode it yesterday and didn't notice any problems. I am a newbie to the forum and not a gearhead either. Any advice would be greatly appreciated. Thanks alot!

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  • grayracer513

Posted May 13, 2007 - 12:45 PM


That is not the "camshaft exhaust". The bore through which oil is being blow out is where the manual decompression shaft once went. Originally, this was occupied by a low rent rubberized plastic plug, which you blew out. You may have something obstructing the crankcase breather. Often that turn out to be one of the metal clips that hold it to the frame below the ignition cover. Either that, or it just got tired of being there.

Either way, the two best ways of fixing it are to use an 18mm brass cup plug (freeze plug from an auto parts store), or one of These from Thumper Talk. You can also replace it with the stock one, but that's not any more permanent than it was in the first place.

  • Pinstripe

Posted May 13, 2007 - 12:59 PM


YOU ROCK!! Thanks for the answer, I thought I had a much larger problem on my hands!! I'm headed to the auto parts store for a temp. fix. Have a great day!

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