Round rubber seal on left side of motor

[fuddrucker]

What is this and how hard is it to replace. Mine has started to have oil seep past it and I was wondering if it is serious or not. It is located on the left side of the head and is about the size of a quarter.

Thanks

[4TraxRider]

i think your talkina bout the timing hole. If thats what it is, just get a new o ring. That'll take care of it.

[jb400exxx]

mine does the same thing, i think it just needs to be tightened or needs a new o ring. so far i have just left it alone and had no problem with it. 4traxrider, he said head, not side case. the seal he is talking about is on the head.