Bolt problem; 78 KX1000A2

Need some advice. Have been rebuilding a 78 KZ1000A2. I bought a NOS head including cam bearing caps and bolts. I installed the cams and started bolting down the bearing caps. My shop manual says to torque to 13.5 ft/lbs. The first bolt snapped off well before I hit the setting. The spec I'm using is 13.5 ft/lbs. Foolishly I continued and had mixed luck with the next five. Some tourqued and some snapped.

I looked at the snapped bolts. They appear to be deffective where the breaks happened. Maybe stress cracking? Not sure. They are 32 years old but so are the ones currently in nthe bike.

Any advice? Should I re-use the original bolts? Try to buy new ones? My biggest problem now is getting the snapped off bolts out of a new head. Patience, patience, patience!

There are some current posts on those cam caps. The Book is wrong on the torque, many people have read that spec and striped the threads out. 1/4" ratchet is all you need, torque is in Inch pounds. Most service manuals also have a guide for torque per bolt/ thread size/ type. Those puny little 6mm bolts will never take 13ft. lbs.

So....what torque spec should I use? I've put enough money into this rebuild that I'm not willing to even turn it over, let alone close it up if I'm going to spin cam bearings! Anyone????

Try here,
kzrider.com/index.php?option=com_kunena&...ew&catid=2&id=395574
There is some discussion on this very issue.

zeerex99 wrote:

So....what torque spec should I use? I've put enough money into this rebuild that I'm not willing to even turn it over, let alone close it up if I'm going to spin cam bearings! Anyone????

I use about 90 INCH-POUNDS on cam bolts. That's about 7.5 FT-LBS but you must have a low range wrench to get it accurate.

yes T/Q 90in lbs you will be good to go

OK; tell us what manual gave that spec?? I'm betting on Clymers. Ed

My factory shop manual for my 1982 GPz1100 B2 model had for the 16 M6x1.0 cam bearing caps as 12 foot pounds, I found out it should have been 66 Inch pounds and changed it in the manual.

I asked because all the Kawasaki factory service manuals (from 1976 up) for the KZ650 show 95-113 IN lbs. That's 7.9 - 9.4 FT lbs. I suspect that the big engine cam caps are different, but 12 FT lbs sounds like a whole bunch if they are 6mm bolts. I set my torque wrench at 100 IN lbs and had no problems. Ed

Possibly this may help someone.
www.imperialinc.com/pdf/A_FastenerTorqueCharts.pdf

Don't know if this is any help but at the Honda factory we use 0.7 - 1.2kgf for any normal 6mm bolt or nut. If you go much more than that, you start stretching the bolt or stud.

The manual that came with this bike is indeed a Clymers. This is my first experience with any manual (car or bike) giving a torque value that far off. Then again, it's the only Clymer manual I've ever used. Haven't tried pulling the broken bolt ends out yet. At least the threads didn't strip on the head.

I bought the factory shop manual when I got my ZRX1100 and there's no comparison to the Clymer manual.