Bearing cap bolt thread repair

I am putting my kz1100 back together after changing valve shims. I have the bearing caps all snug but I can't get the torque to develop on some of the bolts. 12 ft-lbs per kawasaki manual. I alreadt have Helicoils in some of suspect bolts. Do I need to re install the Helicoils or can I just use a thread locker or chemical thread repair? Any suggestions? Yes I am using a certified torque wrench and I am stopping as soon as it clicks.

I believe there may be an error in the manual. 12 foot pounds seems very high for those 6mm bolts. The spec for the KZ650 6mm cam cap bolts is 95-113 INCH pounds which is about 8 - 9.4 FOOT pounds. I never torque mine above 100 INCH pounds. Perhaps someone on this site has an updated manual for the KZ1100 that shows a revised torque figure for your bike.

I have two recommendations -

Replace the helicoils with Timeserts. They provide a true, permanent fix. See www.timesert.com

Use a torque wrench calibrated in INCH pounds and set it to the inch pound spec for the bolts. The problem using one calibrated in foot pounds is that those normally have a higher torque range. Even the world's best torque wrenches are not accurate below 20% of their maximum range. So, for example, if a torque wrench has 100 foot pounds as the highest number on its scale it will not be accurate below 20 foot pounds.
Ed

650ed wrote: I believe there may be an error in the manual. 12 foot pounds seems very high for those 6mm bolts. The spec for the KZ650 6mm cam cap bolts is 95-113 INCH pounds which is about 8 - 9.4 FOOT pounds. I never torque mine above 100 INCH pounds. Perhaps someone on this site has an updated manual for the KZ1100 that shows a revised torque figure for your bike.

I have two recommendations -

Replace the helicoils with Timeserts. They provide a true, permanent fix. See www.timesert.com

Use a torque wrench calibrated in INCH pounds and set it to the inch pound spec for the bolts. The problem using one calibrated in foot pounds is that those normally have a higher torque range. Even the world's best torque wrenches are not accurate below 20% of their maximum range. So, for example, if a torque wrench has 100 foot pounds as the highest number on its scale it will not be accurate below 20 foot pounds.
Ed

Ed is 100% spot on...8-9 ft lbs...use a torque wrench calibrated in inch lbs to be more correct (e.g. 100 in ch lbs or so). If the caps cannot be torqued, then the helicoils may already be stripped and do need to be replaced...Timeserts can be a bit pricey but with a bit of practice, provide a surefire solution (this is what I had to do on my GPz1100).

Mcdroid wrote:

650ed wrote: I believe there may be an error in the manual. 12 foot pounds seems very high for those 6mm bolts. The spec for the KZ650 6mm cam cap bolts is 95-113 INCH pounds which is about 8 - 9.4 FOOT pounds. I never torque mine above 100 INCH pounds. Perhaps someone on this site has an updated manual for the KZ1100 that shows a revised torque figure for your bike.

I have two recommendations -

Replace the helicoils with Timeserts. They provide a true, permanent fix. See www.timesert.com

Use a torque wrench calibrated in INCH pounds and set it to the inch pound spec for the bolts. The problem using one calibrated in foot pounds is that those normally have a higher torque range. Even the world's best torque wrenches are not accurate below 20% of their maximum range. So, for example, if a torque wrench has 100 foot pounds as the highest number on its scale it will not be accurate below 20 foot pounds.
Ed

Ed is 100% spot on...8-9 ft lbs...use a torque wrench calibrated in inch lbs to be more correct (e.g. 100 in ch lbs or so). If the caps cannot be torqued, then the helicoils may already be stripped and do need to be replaced...Timeserts can be a bit pricey but with a bit of practice, provide a surefire solution (this is what I had to do on my GPz1100).

Ok. I will get the timeserts. My wife keeps admonishing me that when I work on something, something else breaks. I just glare at her. I can probably get them to click at the lower torque.

With my last two (virgin) J-heads, I've had no issue with the manual torque specification (12 ft. lbs), and have pretty much eliminated the problem of stripping threads by tightly clamping the cam caps prior to insertion (and removal) of the bolts...then finger tighten to seat, and careful-incremental torquing to spec.

I think the problem either starts with poor aluminum casting quality, or PO's using less care when installing cams. IMO, you just can't rely on 6mm aluminum female threads to stand up to repeated stress exerted on them when drawing cams/caps down with the bolts.

This is why the first thing I did before sending my head out was to install heli coils in all 16 of the cam cap holes...... would have taken the advice on here and did Timeserts but I have at least done a few heli coils before and I was worried about it enough already.

I always stop at 80 inch lbs too........ Doing them by hand (before buying the wrench) I would of stopped at 60 to 65 inch Lbs so I guess that's why I never stripped one before including the valve cover.

I have ordered the Timeserts hopefully, I can get this together on saturday. I am just looking to get it running before winter and then will evaluate whether I pull the trigger on the chassis mods I have assembling parts for. If I have to pull it apart again, I will make sure I take the time to push the cams in with clamps first.