Which head gasket for a KZ1000ST?

Hello,

I need to order a head gasket of my '79 KZ1000ST. I went to Z1-Enterprises to look at what they sell. I found several head gaskets:

Head Gasket 1045CC 71MM - .043" Copper - 2 Piece

Copper Head Gasket - 10MM Dowel Pin - 71mm 1015CC .043" Copper

Copper Head Gasket - 10MM Dowel Pin - 72mm 1015CC .043" Copper

Head gasket - sold individually, two required

I would like your opinion.

Is copper better? Which one is better: 1 or 2 parts gasket(s)?
As regards to the 1 piece copper gaskets, are 71mm and 72mm the bore diameter?

The latest model (not copper / 2 parts) looks like what is currently installed on my bike.

Thanks for the help!
Nicolas.

Whaoo! Z1-Enterprises already replied to my mail. I didn't think they would be so quick. They explained me the first 3 gaskets are for oversized bore. Since I think (I'll measure everything on next WE) the pistons of my KZ weren't changed, I'll order the last one.

The reason that copper head gaskets are sold is I think that the go-fast crowd likes them. I THINK the reason is that they can be reused but I have also heard that they tend to leak oil a bit. The bottom one can't be reused but will seal better. Your pistons are 69.7mm diameter if they are stock so the others, as you noted are NOT for 1015cc bikes... I think they really mean a 1015cc block that has been bored. Also, when you install the gasket you bought, but the oval metal part UP during install. On one side, the metal around the pistons is round and the other side, it is oval.

The reason for the copper gasket is on very high compression motors, you can run an o'ringed block. The o'rings require a copper gasket.

Jay

Hope you don´t mind I borrowed this toppic. Anyone used stock size cylinder (1015ccm) gasket on 71mm (1045 ccm) bore? Can it be done? The diameter of the gasket holes is 71,10 mm. Tight fit..

Yes! you'll be ok with the stock size gasket.