KZ1000/1100 cam cap torque. error?

The 81-83 KZ1000/1100 FSM pdf cam cap bolt torque is listed as 12.0 ft-lbs. is this an error?
The 83-85 GPz1100/KZ1100R factory supplement manual also lists the same cam cap torque (12.0 ft-lbs).

I've read topics in the past in which some guys have snapped off 1 or more of their cam cap bolts & supposedly the listed torque is wrong in some KZ1000 manuals, but I never know exactly which 1000 or manual. Thanks.

Greetings Martin...the manuals are indeed wrong...they should read 8 to 9.5 ft/lbs at a maximum (8 is safer). Actually, that torque rating should be presented in in/lbs as that would be more precise...and should read 96 to 114 in/lbs. I am one of those who has stripped cam cap bolts with the 12 ft/lbs setting.

Excellent question.

If you look at Page 31 at www.kzrider.com/modules/ServiceManuals/K...op%20Manual%20Z1.pdf you will find the Z1 Kawasaki Service Manual specifies 105 INCH pounds which equals 8.75 foot pounds.

If you look at Page 37 at www.kzrider.com/modules/ServiceManuals/K...Service%20Manual.pdf will find the KZ1000 Kawasaki Service Manual specifies 95 - 113 INCH pounds which equals 7.92 – 9.42 foot pounds.

Clearly neither of those specs is even close to the 12 foot pounds recommended in the later manuals, so something seems amiss with the 12 foot pound figure. Ed

By Mcdroid: Greetings Martin.... the manuals are indeed wrong... I am one of those who has stripped cam cap bolts with the 12 ft/lbs setting.

Thanks. I think you left out a big ole' doh .

Ed, thanks. I checked several other KZ fsms, including a Z1 pdf, and they are all in INCH-lbs. But I was thinking that perhaps Kawasaki beefed up the cylinder head for the motorcycles in question.

I went to 12 ft. lbs. with little hesitation on my last J-head and the 84 that is on the bike now. The previous two J-heads were not up to it, whether because the metal was weak, or they were abused by PO's. I had a couple threads pull out that looked like springs, wrapped around the bolts, which I attribute to the bolts being used to draw the cams down, instead of other means to seat the caps before installing the bolts.

In the torque tables of that KZ1000/1100 manual, almost every other M6 bolt has a specified torque in inch-lbs. The camshaft sprocket M6 bolt torque is listed as 11.0 ft-lbs. not sure if that's correct or not, but I think it is.

daveo wrote: I went to 12 ft. lbs. with little hesitation on my last J-head and the 84 that is on the bike now. The previous two J-heads were not up to it, whether because the metal was weak, or they were abused by PO's. I had a couple threads pull out that looked like springs, wrapped around the bolts, which I attribute to the bolts being used to draw the cams down, instead of other means to seat the caps before installing the bolts.

The spring-like threads that pulled out were previously installed heli-coils...usually installed because the bolts were previously over tightened. I have subsequently gone to Time-Serts.

Nope...but helicoils were installed to replace them.
I think the threads had been pulled loose by repeated over-tightening of the bolts over time, or where too much torque had been exerted when the bolts were started into the first few thread turns...which is exactly what happens when the bolts are used to pull the caps/cams down.

Think about it...at-least 12 ft. lbs. of torque gets applied when using the bolts to draw the cams down, and that alone is enough to weaken and pull soft/weak aluminum threads out :whistle:

Problem solved:

Read about so many stripped cam cap threads before I sent my head in I went ahead and heli coiled all of em first and I stop at 70 inch lbs plus a slight double check that probably raises it to 75-80 tops. Knew I would have them out more than a few extra times checking the used 750 cam bearing clearance with plastigage and bench shimming.

Different animal but my Clymer says 81/2 lbs and the factory manual states 95 to 113 inch lbs...... when I bench shimmed my valves just for kicks I tightened the cams to 40 inch lbs and checked a few then re checked at 75-80 and could not read a difference.

I have two factory Kawasaki KZ1000 shop manuals in house. One is for 77/78 KZ1000's, the other is 78/80 KZ100's. On the page for cam caps, both say 78 to 95 inch pounds of torque for the cam caps. My Kz900 factory manual tells me to use 104 inch pounds. No where does it say to torque them to 144 inch pounds!!!! I would not use more than 90~95 inch pounds of torque on the later model KZ1000's and 1100 heads.

I have always used only 90 inch pounds of torque on my cam caps. Since 1974 I have NEVER stripped any cam cap threads!!!

Here is another trick I have used when installing big lift cams in KZ heads. Go buy yourself some 6X50MM or 6X55MM bolts. Replace the standard 6X45MM bolts with the slightly longer bolts, and bring your cam caps down to about a 1/8 of an inch of the head. Then one by one replace the longer bolts with the standard 6X45MM bolts, and then bring the cam caps all the way down to the head, and torque to 78 to 95 inch pounds. You can use the longer bolt trick with stock cams too!! If you strip the cam cap threads using the longer bolts, I would suggest you find yourself another person to assemble your motors!!! Don't save a few pennies, and buy some cheap-ass hardware store bolts either. Fastenal sells a high quality bolt.

I agree with the 100 I-P maximum. But make sure you have an accurate (low range) torque wrench. Most have their accuracy specified as a percent of FULL RANGE so a 200 I-P (full scale) wrench would be perfect.

I have too many miles and camshaft removals to stress in highest priority, don't over torque these bolts. 12ft/lb you will strip threads, 100"/lb you will strip threads. Notice the valve cover 6mm bolts are spec to torque to around 5-5.5ft/lb or 60-66"/Lb. Same size bolts and same aluminum head material the camshaft caps are threaded into. A 6mm bolt into aluminum will only tighten to 60-66"/lb.on these engines, or stripped threads will be common. Exhaust side strips more frequently for some reason. No reason to risk it by tightening to even 100"/lb. The caps aren't going to come loose.