Cylinder Head Nuts Over-torqued

I think I've done a bad thing. I have a 82 kz550 (A I think) that has been leaking oil from the head. So I read this thread about re-torquing a 650. www.kzrider.com/forum/2-engine/591669-head-re-torque-process

I set my torque wrench to 42lbs/ft and crank away. Some of the nuts were pretty tight and didn't require any more, but some felt really loose at this torque.

So then I look up what I think is my manual s3.amazonaws.com/gpzweb/Mnls/Kz400500550...ase99924_1018_06.pdf , Thanks Loudhvx! and it says "Cylinder head nuts - 16.5 ft-lbs)"

Now what should I do? Should I leave them at 42ft-lbs, or back them off and re-torque to 16.5 ft-lbs? I'd like to tear this thing down next winter and do a rebuild on it, but I won't have the money to do it until at least then. Thanks for any advise.

I would back them off and retorque to the correct number. I would be concerned about breaking a bolt or stud or stripping threads in the crankcase.

42ft/lb is too high, but 16 is too low. I believe about 25 or so is the spec. I doubt 42 hurt if nothing stripped, just leave alone would be my advice.

16 ft lbs is the stated specification for the cylinder head nuts. The cylinder head bolt spec is 104 INCH lbs. See page 40 in the Kawasaki Service Manual at:

www.kzrider.com/modules/ServiceManuals/Kz400500550_79to83.pdf

Ed

My mistake, by memory I thought higher than 16ft/lb.

A 650 calls for 27 to 31 I think so I went 29ft lbs so its defently higher......... 42 is for the APE HD studs.

30 for my Z1. Don't the APE studs go in further? I'd back off the nuts to 27-30.
Steve

Thanks for the input guys. I backed them off and re-torqued to 16. I found the
partzilla list that Nessism posted for the 750 gaskets . That list comes to about half what I paid for the bike. I found the Vesrah Complete Gasket Kit VG-455 for $81. I know people have said not to use the green gasket that can come with these for the base or head gasket Could I use the rest of this kit and buy the base and head gasket separately or would you say the whole kit is junk?

The 400/500/550 bikes use 8mm cylinder head nuts.
The 650/700/750 bikes use 10mm cylinder head nuts thus the torque is higher.

I'd back off the torque to the spec requirement. Remember, before tightening and torquing a bolt it's important to break the bolt loose by loosening it first, and then tighten it to the spec. The nuts often make a crack noise as it first breaks loose. The static friction can be quite high on a fastener that has not been moved for some time. A little lubricant on the threads doesn't hurt.