Help please - think I'm going to cry....

[Sergeant Pluck]

OK - I just fired the bike up and immediately noticed that the right hand side was louder than the left. Had a closer look at the RHS cylinder and found I can feel air blowing from between the fins on the top of the head - in between the rocker cover and the head gasket, as if (dare I say it) there was a hole in the head.

Bikes an 1150 BTW....

Does this sound like what I think it sounds like or bow) or could there be another explaination?

Cheers in mild state of panic,

 

[MikeP]

Is the blowing inboard of the exhaust?

 

[adamski49]

Could it be as simple as the exhaust header blowing? Have you checked the two nuts that secure the header to the head?

Just an idea.

Adam

 

[Sergeant Pluck]

Yeah I waved my hand around the front near the exhaust bolts and there's no air there - it's definately coming up between the fins on top of the head....

 

[MikeP]

Try some soapy (washing-up liquid) water on the area. Watch for bubbles.

 

[Sergeant Pluck]

Yep - definately blowing - spark plug suggests lean running on that side too.

Head Gasket? Hole in head ? Something very simple I hadn't thought of?

 

[MikeP]

The most likely is the head gasket but it would be blowing between the fins where the gasket is. Your posts seem to be suggesting it blowing between the head gasket and the rocker cover gasket!

 

[Sergeant Pluck]

Well this is a total mystery. Yes it was blowing up between the fins between the head gasket and the rocker cover BUT;

I've just whipped the rocker cover off again to have a shifty - put it back on again and the problem has disappeared!! Very feckin weird. The only thing that I can think of is that the donut rubber ring between rocker and head that goes around where the spark plug screws in was mis-seated - but why the air between the fins?

Going for a run now to see if it stays sealed!!!

 

[Timolgra]

Don't drink so early in the day it confuses things

 

[Mouse]

Ait will blow from the rocker cover seal if it's not right, because the space inside the rocker cover is connected to the crankcase, therefore as the crankcase volume changes (as the pistons move) air gets pushed ino the rocker space. Normally if you have no leak of course, the air will move through the breather hose to the airbox.

 

[Iain Hogg]

There is a rubber gasket around the plug hole in the head, it can be dislodged when you fit the rocker cover. Symptoms as described.

DAMHIK

 

[Sergeant Pluck]

There is a rubber gasket around the plug hole in the head, it can be dislodged when you fit the rocker cover. Symptoms as described.

Yep - it was that - if gets 'squigged' when you replace the rocker cover it blows air up through the gap and out in between the fins. Alarming - but panic over!

Thanks for the replies.

 

[Steptoe]

Yep - it was that - if gets 'squigged' when you replace the rocker cover it blows air up through the gap and out in between the fins. Alarming - but panic over!

Thanks for the replies.

You always put the large "O" ring onto the rocker cover before you replace it -

if you replace the rocker cover with the "O" ring still inside the head, as well as blowing, you also stand a good chance of splitting it and getting an oil leak - believe me .

 

[Sergeant Pluck]

believe me

Oh I do! When I'm working on my bike - if there is even the remotest possibility that something can go wrong, it definately will ;-)

Although to be fair to myself - I just did the full 24 thou service plus one or two other bits, and I only stripped one bolt during the entire process, so I'm secretly quite pleased with myself....