Today after riding I noticed that my motor was covered with oil and found that the valve cover gasket was blown out (a 1" section protruding out between the valve cover and the head on the front side).
My bike was set up by the previous owner to have the valve cover breather hose draining directly through a single vent tube without a plug on the end - the stock vent hose is set up with a plug on the end of it (read below). I have been riding the bike with this set up for months without any issues. The problem I had with the blown valve cover gasket occurred after I changed the vent tube set up back to stock.
The stock vent tube set up comes off the valve cover port and meets up at a "Y" junction with another vent tube that is coming off the air cleaner box. These two vent tubes meet at the "Y" and collect into a single vent tube that proceeds down to a spot near the crank case located just inside of the front sprocket. The end of this tube is closed off with a plug that is held in place with a pinch clamp. Per the owners manual, you are supposed to remove this plug periodically to let any built up fluid drain out.
For whatever reason, I decided to take the vent hose set up from the modified set up (single vent hose without a plug) to the stock set up (two vent hoses merging into 1 hose with a plug). The first ride after I changed things back to stock is when I had this problem.
My question is: What could have caused this to happen? My guess is that because the end of the tube had a plug in it, the back pressure from the plugged tube caused the gasket to blow but I would also think that the stock set up should work just fine. I will taking it back to the custom set up.
Any thoughts would be appreciated.
Thanks.
My bike was set up by the previous owner to have the valve cover breather hose draining directly through a single vent tube without a plug on the end - the stock vent hose is set up with a plug on the end of it (read below). I have been riding the bike with this set up for months without any issues. The problem I had with the blown valve cover gasket occurred after I changed the vent tube set up back to stock.
The stock vent tube set up comes off the valve cover port and meets up at a "Y" junction with another vent tube that is coming off the air cleaner box. These two vent tubes meet at the "Y" and collect into a single vent tube that proceeds down to a spot near the crank case located just inside of the front sprocket. The end of this tube is closed off with a plug that is held in place with a pinch clamp. Per the owners manual, you are supposed to remove this plug periodically to let any built up fluid drain out.
For whatever reason, I decided to take the vent hose set up from the modified set up (single vent hose without a plug) to the stock set up (two vent hoses merging into 1 hose with a plug). The first ride after I changed things back to stock is when I had this problem.
My question is: What could have caused this to happen? My guess is that because the end of the tube had a plug in it, the back pressure from the plugged tube caused the gasket to blow but I would also think that the stock set up should work just fine. I will taking it back to the custom set up.
Any thoughts would be appreciated.
Thanks.