Just blew out my valve cover gasket...oil everywhere
 

Was riding nicely in the city and noticed smoke suddenly all around me.


I got the bike home (which was close).
I removed the tank and found oil all over the outside of my rear cylinder.

I started the bike up and found the problem.....the vavle cover gasket!

There are 4 "half moon" shaped rubber plugs that are part of the gasket.
Two of them had blown out.

I have never seen this ever happen on a motorcycle, Ihave never even heard of it happening to a VTR.

I am ordering a new gasket in the morning. What really concerns me is why it gave away. The bike was not over filled with oil. I am going to check the breather hose in the morning to see if it's blocked.

Other than that, I see no other reason why the gasket would blow out like that.

The only other thing I can think of is a plugged PCV type valve that connects to the breather hose on the top of the valve cover. I am not sure if there is one cause I don't see one in the shop manual.

I am guessing it must be underneath the valve cover but I can't say for sure until I remove the cover.


Any suggestions would be appreciated. Is there anything I may be overlooking?


I'll keep you guys posted.

IGeorgeI

Re: Just blew out my valve cover gasket...oil everywhere
 

was going to suggest checking breather hose,where it goes into the airbox....i took mine off and it was full of water at the air box end! :shock: must of been condensasion,ive had no leaks since .but the cover gasket wasnt blown out like your just weeping under the pressure i guess.cheers.

Re: Just blew out my valve cover gasket...oil everywhere
 

Yes, this is very un-honda like. I too would be thinking a pressurization problem.

How old/miles is the bike? If relatively new, the gasket might have just be installed improperly and now gave way. As I said, very un-honda like but it does happen.

Re: Just blew out my valve cover gasket...oil everywhere
 

She's got around 20 000 km and it's a 2000 VTR.

No smoke coming out of the pipes so I am going to assume that nothing internally cracked or gave away. On the ride home she still had lots of power.

I am just having a huge problem believing that the gasket just blew out under normal conditions like that.

When I get home from work I will check the breather hose to the valve cover. If that's all clear then I will install the new gasket that comes in on Monday and go for a ride.

IGeorgeI

It takes a lot of force to blow those cam plugs out.
You've had a crankcase explosion.
The same thing happened to me.
If something causes your air filter to become somewhat blocked (oil soaked, in the case of a stock paper filter) causing a very rich condition.
The crankcase can fill with combustable gas.
Then a backfire can light it though the breather. The resulting explosion is more than the crankcase venting can handle, and it blows the plugs out.
Mine happened after I over oiled a K&N air filter.
The K&N filter oil spray cans nozzel was sort of plugged. And I was in a hurry and sort of dribbled
the stuff on, and got too much on. I rode 100 miles to a ride meet in Porterville, filled the tank, started the bike a KERPOW I was ingulfed in oil smoke!
Quite a crowd pleaser I might add for all of us at the ride start!
I blew 6 of the 8 cam plugs out.
So check your airfilter.
If it's a stock or paper filter and If the bikes been on it's side it might be oil soaked and still and look fine.
If it's a K&N or oiled filter, it may be over oiled.

I pushed the cam plugs back in the valve cover in Porterville and rode the bike home, where I sat down to figure out how I 'blew up' my crankcase.

~Jeffer

Re: Just blew out my valve cover gasket...oil everywhere
 

Regardless of what the fuel source is, the spark is the issue.
You may frown or even laugh at this but if you think about it, there is no way an ignition source can get into your crankcase, save for one.
Your stator.
You likely have at least one stator coil that is arcing to ground, setting off your combustibles in the crankcase.
Pull off your left engine cover and take a look.
If I'm wrong I'll send you a replacement gasket.
Kai Ju

Before you consider all of that, have you had the cover off recently?

Re: Just blew out my valve cover gasket...oil everywhere
 

Excellent point and really is the first question that should have been asked.
Kai Ju

Re: Just blew out my valve cover gasket...oil everywhere
 

I have never had that cover off, it's original.


Here is the update.

I took off the cover tonite and checked:

1) bolts on valve cover were tight
2) breather hose to air box was clear
3) breather hose fitting on valve cover was clear

The Gasket is in nice shape and the valve cover is being vented properly.

I am going to have to go with the theory that the caps on the gasket blew out due to sudden preasure from an explosion.

my bike is running rich soooo.................

The back fire in the airbox which detonates a build up of gas fumes in the valve cover seems to be a good theory. That could have happened a while ago and simplly pushed the caps out partially. Over time the caps just came out all the way.


I am going to try and reuse the stock gasket and see what happens



IGeorgeI

Some pics
 

For those of you who don't know what we are talking about, here are some pics.

The steel braided lines in the pictures is for my 40 HP shot of nitrous.

Re: Just blew out my valve cover gasket...oil everywhere
 

Ok, I replaced the rear valve cover gasket and resealed the front one. I sealed both gaskets with RTV silicon on both sides. Honda only glues one side of the gasket.

I also vented both valve covers to open air using tiny atachable filters.

While I was there, I also removed the hoses inside the airbox and the tiny white oil collector in the air box.

This leaned out my bike and gave me better throttle response and more power from 4 thousand RPM all the way up.

It was a great mod for me cause I was running rich to start with.

All in all the bike is now running better than before and there is no way those valve cover gaskets will blow out again.....hopefully.

Thanks for everybodys help

George