found stripped cam holder bolts

kz900 FSM, page 31, 104 in-lbs.

that makes sense to me and i beleive with such light torque i will simply drill and retap the hole and put in i beleive would be 1/4-28 that was suggested earlier.what do you guys think?which such light torque do i really need to put in a heli coil or a insert?

Id go with the heli or timecert there both stronger than just a retap.Ive been using helicoils for years and never had one fail.If you choose to just retap go with 1/4-20 a course thread is stronger.And id only torque to 7 or 8 ft lbs with a bit of red locktite

Patton wrote:

As a matter of reference - - -

KHI FSM Mar. 12, 1979 [Part No. 99931-540-03] covering '77~'79 KZ1000 specifies
95~113 in-lbs.

KHI FSM KZ900 Mar. 28, 1977 [Part No. illegible ] covering '73Z1~'76KZ900 specifies
104 in-lbs.

Chilton's Kawasaki 900Z1 Repair and Tune-up Guide 1973-1974, 1974 First Edition covering '73-'74Z1, specifies
105 inch pounds.

12 ft-lbs is 144 in-lbs, and obviously too tight by almost 50% over-torqued, at least for the large Kawasaki fours through 1979 models.

Am wondering exactly which manuals contain the bogus information?

Apparently all KHI manuals for 'J' motors. This would be the KHI manuals for the KZ1000K,M,R, and J and the KZ1100B series. By extension, also the ZX1100A series and the KZ1100R1 (since the base manual for the these bikes is the KZ1000/1100 manual). Additionally, the shaft-series KZ1100A,D, and L also all have recommended torques of 12 ftlbs (= 144 inchlbs). I suspect this also applies to P models as they use the 1000/1100 manual as the base manual (but I have have never thumbed through a P supplement to see if it was emended).

RonKZ650 wrote:

I'm not a mechanic and don't know what a parkerized bolt even means, but the bolt is not the problem, it's the aluminum in the head that strips, particularly the exhaust side. I don't know if it's the heat from the exhaust or just material is weaker on that side of the head, but they will strip at 7 ft/lb. Oops don't do ft/lb. They will strip at 84 in/lb the same exact way:) . It's not like the cam caps ever vibrate loose, so why in the world risk stripping? Torque to 60-65 in/lb.

Good point.

I've never stripped anything at 90 in/lbs, but I have stripped an oil pan bolt or two at 95.
Just never in the heads I've done.

The FSM specs are not wrong. There are 2 different torque specs for the 2 different bolt types. Both work just fine for their associated design if you know what you're doing.

The problem isn't the bolt nor the head. The problem is the guy with the bolt and the wrench in his hand that caused the threads to strip.

There's the bolt and the hole. The bolt cannot put itself in to the hole, it requires human intervention....

Along comes the human....screws the whole process up Then seeks to put the blame on the bolt and or the factory service manual..... :silly:

What sucks is you never know which human was in there messing with the bolts before you got there.:laugh:

All the SOB motors except the 83-85 GPz11 model, use 2 bolts per cam cap. Rarely do you see stripped out cam tower bolt holes in those engines.

The 4 bolt cap design has problems.

larrycavan wrote:

The FSM specs are not wrong. There are 2 different torque specs for the 2 different bolt types. Both work just fine for their associated design if you know what you're doing.

Hmmm...but you admitted to not following the Kawasaki specs of 12 ftlbs and using less torque.

I found the same problem with my J head, like Larry said it is a 4 bolt cap type. I actually broke a bolt off in the head and then stripped out 2 holes. My manual is the kz1000/kz1100 FSM, if there are more of these errors in manuals maybe we should start a sticky? anyways, Scubarod here is the helicoil set I got if you choose to go this way, I got it fast and it worked great.

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The cheapest solution I've found for this is to use thread inserts described in this post . About $1.00 per insert, and no special tools needed (other than drill bit, tap, & screwdriver).

As for tapping the hole with the head still on the bike, the method I uses is to cover the open head with a sheet of aluminum foil. Then I press down over the hole area until I find the impression of where the hole is. I then smear a good glob of grease around that spot, then drill the hole. The grease catches the shavings, and the rest of the head is covered and protected by the foil sheet.

The damage that causes the failed threads is done long before the bolt reaches FSM torque spec. It happens on the way to that point.

Kawasaki FSM's for new models would arrive and then some later point in time, corrections to misprints would arrive. So yes, there are incorrect specs in service manuals, even from the factory.

However, the cam tower bolt specs were correct for the KZ and J motor cam towers.

RonKZ650 wrote:

I'm not a mechanic and don't know what a parkerized bolt even means, but the bolt is not the problem, it's the aluminum in the head that strips, particularly the exhaust side. I don't know if it's the heat from the exhaust or just material is weaker on that side of the head, but they will strip at 7 ft/lb. Oops don't do ft/lb. They will strip at 84 in/lb the same exact way:) . It's not like the cam caps ever vibrate loose, so why in the world risk stripping? Torque to 60-65 in/lb.

mine vibrated loose and spun some bearings racing an RC-51. I rode it for 25 miles with smoke out the left pipe. I use loctite at the top threads now too. Just get some harder bolts and the certs and close the book on cam bolt problems. Don't even think about tapping out yet!