what is this...

[waterdog3]

I noticed that a bolt is missing from the head. Right side, just behind and above where the header meets the engine. actually on the right side "exhaust valve". what is it and can i just plug it??????????????????

[waterdog3]

when the engine is running i could feel the exhaust pressure coming out of the hole, just like when you put your hand behind the exhaust pipe.

[Dan_Lorenze]

Hmm... What bike?

[CRFThumper]

I noticed that a bolt is missing from the head. Right side, just behind and above where the header meets the engine. actually on the right side "exhaust valve". what is it and can i just plug it??????????????????

Decomp plug?What year bike is it?If it is a 03 or newer I bet thats what you are talking about!Look at the tt store page ,a guy on here maks cool plugs for it! ?

[waterdog3]

04 Wr450.............can You Just Plug It Or Do You "need" The Special Decomp. Plug?????

[CRFThumper]

Well you could just plug it but I would be worried that it would fall out again!Maybe just plug it till you can get a REAL plug.

[waterdog3]

Can You Plug It With A Bolt???there Are Threads In The Hole....or Does It Need To Be A Rubber Plug Of Some Type That Could Be Blown Out If Needed???????????

[Hamish]

is it on the side of the head or the front?

could be the decomp plug(front) , or the decomp retaining bolt)side).

[CRFThumper]

Can You Plug It With A Bolt???there Are Threads In The Hole....or Does It Need To Be A Rubber Plug Of Some Type That Could Be Blown Out If Needed???????????

Nope no theads it's just a rubber coated plug from yamaha.The one the guy makes is alu and is anodized blue!!

[waterdog3]

I got to looking and the actual decomp. plug is there. The retaining bolt that goes through the "SIDE" of the head is whats missing. I have put in a bolt to plug it and my bike went back to normal. With the plug missing the bike had a very very bad bog and knocked the power down some. and was a bit@h to start. Now no bog,1 kick starts, and wheelies that never end. Who would have thought.....................

[CRFThumper]

Good thats even better! And a easy fix to boot.Glad it came out ok!!! ?