Piston recommendations

My motor doesn't need it but you know how we like to tinker. Just thinking about a rebore for my '79 KZ1000. Maybe a 1075cc kit, it seems to be popular.

How about compression? I see 10.25 - 10.5 on the higher end and 8.5 - 9~something on the lower end. Will a motor ping on regular gas with 10.25 - 10.5 compression? I am thinking of going with the lower compression pistons for safety but also think the extra compression would be great for the midrange.

10.25 is fine on regular/unleaded gasoline....

If you still desire the low to mid range zip.... Throw some .365 lift cams w/a 4-1 exhaust in there as well...

Oh hell, since it's your money.... Throw some 29-31mm Kehin Cr's on there... :evil:

Hell...it's just money...we can always make more! Easy it is to spend other people's money? lol

OMR...what did you degree those cams in at?

Since it was my first CAM degreeing run, 105 Lobe centers on the nose....

Larry has mentioned about a change to 106 on the intakes, 104 on the exhaust...

I'm thinking about it but she's running so damn fine I hate to mess with her.... Just enjoy her for the time being for she truly is an amazing ride as is...

Maybe the next one since I've been through the process and am comfortable with the procedure...

Here's the specs for the WebCam .365....

Thanks for the info. I would probably start with a 1075cc rebore and see what happens.

My KZ1000 seems to be healthy but it doesn't exactly knock my socks off with acceleration. Of course I've had some newer bikes - two ZRX's, a Speed Triple that's probably why I don't think this one is fast.

On the other hand, too much power can be a problem. A speeding ticket increases my insurance rates for three years, don't need that.

BTW the KZ is currently running a Kerker pipe, pods with 20 pilots and 120 mains. The carbs are Mikunis off a GS1000. Not sure about the details but I they are VM's, 26mm I think.

Old Man Rock wrote:

10.25 is fine on regular/unleaded gasoline....

What octane are you considering regular?

I was under the impression you had to run 91/93 octane/high test with 10.25:1.

There was a discussion about this awhile back...

Here in AZ, can't even find leaded regular any longer... Some of our members posted where still available in their areas... Can't remember what octane they used... Use the search function, maybe find it...

@ 10.25, racing fuel not required is what I was truly indicating.... Unleaded gasoline...

Old Man Rock wrote:

There was a discussion about this awhile back...

Here in AZ, can't even find unleaded regular any longer... Some of our members posted where still available in their areas... Can't remember what octane they used... Use the search function, maybe find it...

@ 10.25, racing fuel not required is what I was truly indicating....

Got it. Just wanted to make sure everyone was on the same page terminology-wise.

Agreed - I believe the generally accepted rating for octane for the upgraded compression is 90+ (Premium). At least Larry says so which is good enough for me.