Cyclinder head Cam Cap bolts stripped

Hi All. i have two bolts on the exhaust side of the head on the cam cap stripped, not the actual bolt but where the bolt goes in.Previously had helicoils, but these have also been stripped. To put in a time insert i need to drill out a 10mm hole. A engineering company said it is to close aganst the cam bearing to drill and when i do it , it will expand and have not enough wall . Has anybody else experienced something like this and what was the recommend fix....thanks

I wish I had a buck for every thread about stripped cam cap bolts........ :blink:

There is a product made by the same folks who do Time Serts...called Big Serts...these inserts are designed to replace helicoils that have failed. I replaced my stripped exhaust camcap threads with Big Serts on my GPz1100 head. They work well as they have a 'cam-lock' feature. However...you must be exactly correct in your placement and depth as these Big Serts are a one shot deal...once they are in...that is it.

The reason your cam cap bolt holes are stripped is that the torque specs in the Kawasaki manual are wrong. When re-torquing the cam cap bolts, go to 96-114 inch lbs, NOT 144 inch lbs.

...and bountyhunter is correct...one of the most common ailments of the J-motors is stripped cam cap bolt holes, because of over-torquing.

Also: you need a proper low range torque wrench. If you don't have one, the Harbor Freight 0-200 I-P wrench works pretty well. I suspect a lot of them got stripped when somebody tried to use a 100 ft-lb wrench and torque to 8 ft-lbs.

I believe there was also a manual that misprinted or overstated the necessary torque spec.

Just a trick to try and not strip them out. When bolting cams in, bolt the side in first that is not going to push a valve down. If the #1 cap has a lobe on the cam that is going to push a valve down then bolt the #2 cap on first. Exact opposite when you remove the cams. Unbolt the most compressed side first.

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> Cam Cap Repair

My KZ750 manual states 104 in-lb, but thanks to this site I found that it was recommended to use 85 in-lb instead, so I changed it in my manual before I changed out shims.