77 kz 650 cam caps

I got some bad threads on one of my cam caps, what size helicoil do I need, is there much involved installing one? Thanks

take bolt to auto parts store with you and match threads.goodluck,happy wrenching!

No doubt 6 X 1 mm.

Jay

Your cam cap bolts are indeed 6mm with 1.00 pitch thread. If the thread is just a bit buggered, run a tap down; clean with solvent and blow the thread out with compressed air. If the thread is RUINED, then go oversize. You have a choice. If you don't care about metric vs SAE, 1/4" works fine as it is just slightly larger than 6mm. You could also go to 7mm if you don't mind looking for an odd size 7mm bolt. They can be found. Most racers replace stripped thread with 8mm bolts due to strength (8 x 1.25 insert). I suggest you consider buying Timesert or most any solid insert rather than fool with Helicoil as that product is a coil of steel that is hard to keep in the hole when you remove the bolt.

If you run bigger than 6mm will the bolt still fit through the dowell pins on the caps is the question. I doubt highly a 8mm would fit. Never used the timeserts, but the Helicoils I've done hundreds over the years and never have had problems with them. Some reason the exhaust caps on the KZ650 will always strip over time. I've done all my exhausts with Helicoils.

Ive never heard of a timesert, is it about the same? Thanks for the info, kevin

In my dragbike all cam cap bolts have been Helicoiled, just be on the safe side. Have had cams out repeatedly with never a problem.

Helicoil it. I had my head off a few years ago and just helicoiled all the cam caps just so I wouldn't have to deal with them while on the bike.
With cams that have to be removed to change valve clearances you would have thought Kawasaki would have installed inserts from the factory. I can't tell you how many of these things I have stripped out over the years.
Oh yeah they are 6mm x 1.0. Good luck