'04 450 Plug Blows Out

3 replies to this topic
  • BBrown626

Posted December 09, 2006 - 02:15 PM


Hi guys.
On my bike, just below the valve cover, on the front right side there is an unused port about 1/2" diameter. There is supposed to be a flat rubber plug in there. My plug blew out. I replaced it and the new one came out after a few minutes too. There is a little bit of air pressire coming from the hole and it blows out out onto the exhaust. The pulses of air vary in pressure. The flow is minimal at idle, almost now flow when revved up a bit and it increases quite a bit when the throttle is cut.

I am concerned that the root cause of the plug blowing out is the pressure behind it. Is it normal to have some pressure there or are my valve guides worns ro something like that? Maybe I was supposed to glue the new plug in?

I searched the forms and couldnt find any information. Any help would be appreciated.

The part is item 15 on the camshaft chain drawing (no idea why it is on there!).

  • dwnlowx

Posted December 09, 2006 - 03:24 PM


Is It The Decompresion Plug And Did You Over Heat

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  • grayracer513

Posted December 09, 2006 - 04:10 PM


There's a lot on the subject. Here's one:


The probable cause is a pinched breather hose at one of the metal clips that holds it to the frame.

  • BBrown626

Posted December 09, 2006 - 05:39 PM


Thanks Grayracer, I greatly appreciate your sharing your expertise on this (as well as everything else). I will check the clamps and order the TT plug.


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