Can cover vs cam cap bolts.

Because of the discussion with Robb2018 and his cam chain issues, reminded me I recently read an article in the file base. It’s a write up on getting top performance out of the Kz900. In the article it says to make sure you keep the cam cover bolts separate from the cam cap bolts. It mentions that although they are similar in looks the cover bolts are made of weaker material. I have heard of several guys snapping cam cap bolts within the torque spec. As anyone heard this and how would one confirm it. Also how would you separate them out of a pile. Here is the paragraph in the article.and a screen shot of the article title. Just thinking this could save us all headaches. 



 

I've never heard of anyone snapping cam cap bolts at the correct torque setting and i've bolted down thousands of cap bolts.
It's only around 8 ft/lb max, the same as the cam cover bolts and well below the yield strength of a standard grade bolt.
I doubt the cover bolts are going to break if used to secure a cap although the correct cover bolts are slightly shorter than the cap bolts so there would be less threads in the hole and more chance of them stripping.
You are more likely to strip the threads in the head if overtightening and this is made more likely even at the correct torque due to the 40 odd year old aluminium casting and stretched bolts point loading and fracturing individual threads.
I never use a torque wrench on the cap bolts and just use years of experience to just nip them up by feel with a 10mm spanner.

 

Zed I agree with all you have said, but as I recall there was an issue with some of the early shop or service manuals that printed the wrong specks and many had to repair the cam bolts.  Now I could certainly be wrong about this as I am older now and do not remember all that I have read. 

wrote:

Because of the discussion with Robb2018 and his cam chain issues, reminded me I recently read an article in the file base. It’s a write up on getting top performance out of the Kz900. In the article it says to make sure you keep the cam cover bolts separate from the cam cap bolts. It mentions that although they are similar in looks the cover bolts are made of weaker material. I have heard of several guys snapping cam cap bolts within the torque spec. As anyone heard this and how would one confirm it. Also how would you separate them out of a pile. Here is the paragraph in the article.and a screen shot of the article title. Just thinking this could save us all headaches. 

 

CAN YOU POST THE WHOLE ARTICLE?
 

That is funny about the cam cover bolts being different than the bolts for the cam caps. Going by Kawasaki microfishe they use the very same bolt part number 92003-092 for the cam caps as the valve cover bolts on the '73~'75 Z1's,'76 Kz900 and the '77~78 Kz1000's!!!!!! Didn't look up the '79 and up Kz1000's. I myself have used that bolt 92003-092 in both locations since back in the '70's without ever snapping one in two pieces!!!!! And since I always have used shim under bucket setups. My cam cap bolts have been removed and reused probably 20 to 30 times!!!! Plus my cams had lifts from .410 to .440 thousands.  

If the Kawasaki part number is the same for both bolts, they ARE the very same bolt!!!!! You don't call and ask Kawasaki for the 92003-092 bolts for the valve cover that are different than the 92003-092 bolts they use for the cam caps.......... Sounds like more internet bull@@@@ to me.

O.E.M. Kawasaki bolts part number 92003-092.
 

.440 lift cams in place using 92003-092 factory Kawasaki bolts.
 

Steve. It’s in our file base.

www.kzrider.com/filebase?task=download.send&id=112&catid=86&m=0

I'm with you Dr.!  Same part number=same bolt.  
It's pre-internet bull@@@@!  You can't believe everything you read in a magazine either,  just someones opinion,  based on their experience.

Mike (who's also torqued "a few" camcap bolts)

Some years ago I learned that early Zeds had black case hardened bolts for the cam caps.  They were 43 mm long.  At some point they increased the length to 45 mm and stopped using the case hardened ones.  This may be the source of the warning but it would be impossible to mistake one for the other, as they are quite different as you can see in the photo.  The thread length is the same but the overall length is different.

There may be a service bulletin for the switch.  I have a PDF copy of them and will check.

 

73 used 92003-092 in both places.
I've only seen black bolts once in ten bikes I've owned, early 75 vin 50k, two bolts broke.

 

wrote:

Some years ago I learned that early Zeds had black case hardened bolts for the cam caps.  They were 43 mm long.  At some point they increased the length to 45 mm and stopped using the case hardened ones.  This may be the source of the warning but it would be impossible to mistake one for the other, as they are quite different as you can see in the photo.  The thread length is the same but the overall length is different.

There may be a service bulletin for the switch.  I have a PDF copy of them and will check.

 

The Z1 parts manual I have was printed in Sept. of 1972 and shows the 92003-092 in both locations.  It is interesting though, that at the bottom of the cylinder head page the is a notation "*Rev: Nov. 30 1972",  maybe that'a when the change was made?

Mike
 

We've never seen black cam cap bolts but we've never worked on very early Z1's either.

The Z1-B parts manual we have that was printed from Mama Kaw's Z1-B fiche covers frame #'s Z1F-047500 - Z1F-085700 and motor #'s Z1E 047500 - 086000 specs PN# 92003-092 as bolts for cam caps and valve cover, same as our Z1 parts manual that covers frame and motor #'s 000001 - 020000.

hardrockminer wrote:
"...I learned that early Zeds had black case hardened bolts for the cam caps. ..."
Our service bulletins only go back to 10/31/72 (the mod for vacuum port nipples falling out of the head).  If you can find the bulletin you mention please share so everyone could update their library.

The error in some manuals wherein too high torque spec for the cam cap bolts is stated is not as well known as it should be.

Good Ridin'
slmjim & Z1BEBE

I took apart 78 and 79 650 engines and those bolts are different. The ones on cover have JIS slots. The ones on cam caps look like dark hardened and no slots, just 10mm socket