Topic: '76 KZ400: how to properly install valve cover after rebuild

[Tugboat]

I know this sounds like it should be intuitive, but I just wanna make sure I get it right. I've posted this on the Kawi Twin Owners Forum as well but am looking for some additional input.

First, the early KZ400's had top-end leaks from the factory. A recall was issued, along with detailed instructions for the dealers to fix the leaks. At least the '75/'76 models had a large o-ring that fit into a groove all the way around the valve cover. There were also these aluminum end-caps for the camshaft that were prone to leaking. Kawasaki's remedy was to replace these aluminum caps with rubber-coated ones, and to do away with the o-ring in favor of using liquid gasket to seal the cover to the head. Per these instructions (just below the motor cutaway), you are supposed to fill the groove with gasket maker and install the cover.

http://www.kz400.com/KZ400D3lFrameset.html

As you can see below, someone (dealer in the 70s?) has already been inside this motor and done at least some of the repairs. You can see where excess gasket maker had been squeezed out when the cover was torqued down, and fortunately it never came loose and blocked my oil passages.



So would the idea be to fill the groove completely to where it is flush with the mating surface and then to sparingly paint the stuff onto the "sides" of the groove - where it will actually touch the head surface? I want to make sure there is enough material to seal it completely without there being so much that it oozes out the inside when torqued down.

Another question: do you let this stuff cure before putting the head cover back on? And if not, how long do you wait for it to cure before you fire the motor up?

[kirkn]

Yep, it's a hard design to get to seal.  But, I did this on my '74 KZ400 about 5 years ago, and it's still leak-free!  But, I was younger and dumber then, and am not sure I'd do it again this way:  I used Permatex High-Temp RTV Silicone Gasket Maker (red).  I filled the groove with it and just did a very very thin 'skim' coat on the groove edges (the surface which touches the head) and around the rubber-coated metal plugs. 

I didn't allow any cure time, but reassembled the cover right away.  I'd let it sit for 24 hours before firing it up, but when I did this before, it was part of a lot of other work, so it sat alright, but not by a consious decision.  I got virtually no 'squish out' and like I say, it's still leak-free today, but if I had to do it again, I'd probably just go ahead and buy the O-ring. 

More recently, I redid the leaking top end on a SOHC Nighthawk 650 and it's the same thing - a complex O-ring all around the rocker box.  In this case, I DID buy the new O-ring.  No further leaks, and no chance of silicone getting where it shouldn't.

Just my two cents.

Kirk

[Tugboat]

After looking in my gasket set, I found that I actually have the o-ring that goes in that groove. Do you think I could use it in conjunction with the newer-style rubber end caps?