2004 Trx450r

[salberts18]

Can anyone fill me in on the reasoning for the small hole in the side casing right behind the exhaust? I overheated yesterday in a harescramble and notice that a small amount of oil leaked out of this hole. Pressure release? After my machine finally kicked back over I noticed that it was missing every once in awhile. Could this possibly be cause by a cracked head?

(Not sure) But is their a rubber tube hooked up to it? If their is then its a breather but if their is no spot for a tube to hook up for then it might not sosposed to be their. I have a yz motor with a hole on the top of the motor with a tube hooked up to it to make the oil drip on the ground instead of on the motor. So if its a breather with out a tube get one or else you will get dirt/water in the motor. If it is a breather a little oil will always be coming out.

[salberts18]

It is not a hole for a breather tube. All the trx450r's have that hole in the side casing, so it is suppose to be there. I just don't know why or what it is for!?!

Originally posted by salberts18
It is not a hole for a breather tube. All the trx450r's have that hole in the side casing, so it is suppose to be there. I just don't know why or what it is for!?!

I think to get rid of pressure in the motor and i heard if you over fill the motor with oil a lot will come out it

[cals400ex]

are you talking about the hole in the right side of the head? if so, this is a drain hole. if you have oil coming out of it more than likely you need to replace a little circular gasket at the top of the spark plug hole. you will have to remove the head cover to do this.