TOPIC:

My top end has been taken to the machinist and now I am preparing for when she comes back.

I have read that the crankcase studs can break if the head has been off several times as they lose there elasticity, So I am wondering what the consensus is on replacing those bolts? I don't want to change them if I don't have to but I also wouldn't want one of them to snap inside the crankcase either. I know the head has been off before due to the pry-bar marks on the base by one or more of its previous owners.

No bites?!! No problems!

Anyway for interests sake here is the link to the technical article I was reading on the Engine Builder website titled: -
Perfect Engine Sealing Starts With Proper Head Bolt Use

Wish I could help but I just don't have the experience there. In the past I never worried beyond making sure everything was clean.

Thanks for the article!
Bill

As a matter of practice, NO, you do not need to replace the studs unless they have been clearly damaged. The kz1300 is not any different to the 4 cylinder air cooled bikes in that regard. Just make sure the threads are clean and that you torque them correctly and recheck after a while.

always change the studs and bolts when ever you are doing head work.. every motor that I ever worked on (and that is many) always went with new hardware.. just my opinion.. always on volkswagens and porche's

Just some thoughts for you to ponder.
First, the service manual doesn't identify an issue such that you are required to replace the cylinder studs. 6cylinder has made it a practice to change out engine hardware and it's not a bad practice. For the record, Volkswagen requires the cylinder head bolts be change out on the diesels because after retorquing 3 times the stretch applied to the head bolts would yield the material so that the applied clamping force was not as much as required. Normally, the stretch on any fastener never takes it to the yield point of the material of the fastener.

Second, One of the main reasons you should consider changing out fasteners that hold aluminum parts together is that all fasteners are steel based and have a sacrificial coating on them of either zinc plating or zinc dichromate. The purpose of the coating is to protect the fastener and the base material from corrosion. If the zinc or zinc dichromate coating is gone or missing from the fastener, then the coating has done its job and the fastener should be replaced.