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Kawasaki KZ550 motorcycle

I recently changed the head gasket on the bike. Air is coming out of the valve covers in a couple spots on both sides of the cover. I removed the cover, the new gasket is still in like new shape and is in tact. Only put less than 30 miles on it. I was planning on adding Permatex to the gasket to hopefully getting a better seal. It was perfectly torqued to factory specifics. I did not tighten the bolts in any order, perhaps I needed to tighten them in some order? My questions are that does it matter which bolt you tighten down first and will Permatex help? Could there be another problem causing the air to come of the the valve cover/head cover?

Are you saying you just tightened each bolt fully, one at a time?

Well i get them snug all then tighten up near torque. Then got a torque wrench and set to right amount.

Without bike in hand I can’t tell you what the problem is but I will say that Permatex is not going to cure anything.

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In answer to your question about order of tightening, start with a bolt near the center and then snug them down in a spiral out towards the farthest from the center. Just a light tight, then again a little more, then a third time at torque. Imagine you are flattening a sheet of aluminum foil on the kitchen counter. You start from the middle and work out to the edges, to avoid wrinkles.

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If this is just about the valve cover, tightening order doesn’t much matter, does it?

In my past experience it was taught to use the prescribed pattern and repeat until up to specs. Cranking down on one bolt at a time can cause a warp.

OP used a 3 step process (snug/almost tight/tight). I’d think that would be fine for a valve cover (not a head).

Putting Permatex also could not hurt. If I recall correct, I did it the opposite way. Stated from the outside bolts instead of the inside. Or I may have randomly went from bolt to bolt. That makes more sense to go from the inside and will do that when I get a chance. Perhaps tomorrow. I believe when I changed head gaskets on my truck the book said to tighten up in a certain order. My book for the bike does not state anything.

Texases, this valve cover is made of aluminum unlike many car/truck ones which are made of steel. I would think that would make a difference in the order you tighten.

I just always do it the way I described; inside out. Why not? It works for me, and taking a few seconds more to get it right makes sense. It’s a pain in the butt to have to go back and do your work all over again.

Taking these covers off is a 10 min job and putting them back on is no big task either. Only thing else that comes off is the tank and coils and wires.

Back to the OP’s question. Doesn’t anyone else fine this odd?
"Air is coming out of the valve covers in a couple spots on both sides of the cover."
I can see some oil leakage, but air coming out?

OP - are you talking about the valve cover gasket, or the head gasket?

I would think you could google proper tightening sequence for those parts on your bike & find some answers .

Could there be another problem causing the air to come of the the valve cover/head cover?

W/a car engine I’d suspect a defective PCV system. Not sure if your motorcycle engine has that feature tho. hmm … well when a piston moves down, the bottom side could pressurize the crank-case & force crank-case air up into the valve cover area I suppose. And if the valve stem seals leaked, that might allow exhaust gasses into the valve cover area during the exhaust stroke. But you’d think the amount would be so little that couldn’t be an explanation. Maybe if both the exhaust valve itself was leaking, ,and it’s valve stem seal was also shot.

I believe it is common for air to come out mostly with very little oil. When the head gasket went out there was mostly air coming out of that also, so the valve cover would be more likely to have air.

“I believe it is common for air to come out mostly with very little oil.”

Not that I’ve seen. If you have high pressure in the crankcase, it may be because you have worn rings and a lot of blowby. Does it burn much oil?

It did not last year. Have not driven more than 30 miles since then.

Always start at the inside of the item you are sinching down… The reason for this is simple… If you were to secure the 4 corners of a square or rectangular shaped cover technically it can bow the center…and also not allow the center bolts to “flatten out” the bow created earlier… This is the way of things.

I never…ever…ever…have any leaks when doing covers…just follow this simple procedure. Just look at any manual for tightening a cyl head… Starts in the center on one side…then the other…then radiating out toward the corners. Never sinch the corners first.

Also…if you have excess air coming out of the valve cover gasket…make sure the PCV is working…it has one. May not be a “Valve Proper” but it does have a way for pressure to escape.


I did just talk to a motorcycle service place and he said that for that age of bike leaking mostly air would have been common. He said to tighten from the center and go out and Permatex should not hurt anything.