1977 KZ1000 Restomod

If you really think you may go for re-sleeving at a later date then you should have the cases bored now to save the extra work and cost splitting the cases later.
As for carbs, 34's are more than enough at 1075.
I always go for the smallest that will satisfactorily feed the engine as this keeps the bottom end crisp.
Too big and the bottom to mid range response will suffer and that's where you will realistically spend most of the time running.

zed1015 wrote: I always go for the smallest that will satisfactorily feed the engine as this keeps the bottom end crisp.
Too big and the bottom to mid range response will suffer and that's where you will realistically spend most of the time running.

Thanks for that - you're right, I don't want to lose any bottom/mid-range response. Will look into the 32's.

You're also right about getting the cases bored. Will definitely get it done regardless of my decision on the pistons/cylinders.

zed1015 wrote: If you really think you may go for re-sleeving at a later date then you should have the cases bored now to save the extra work and cost splitting the cases later.

This was another question, I wasn’t sure if you had to match the case bore to the spigots. Good to here you can use a larger case bore with smaller sleeves. Is there a limit to size difference?

Calum, sorry to be double teaming here but the information will benefit all of us.

Mikaw wrote: Calum, sorry to be double teaming here but the information will benefit all of us.

I'm not usually up for double teaming but in this case it's absolutely fine

calum wrote:

Mikaw wrote: Calum, sorry to be double teaming here but the information will benefit all of us.

I'm not usually up for double teaming but in this case it's absolutely fine

Thank you

Mikaw wrote:

zed1015 wrote: If you really think you may go for re-sleeving at a later date then you should have the cases bored now to save the extra work and cost splitting the cases later.

This was another question, I wasn’t sure if you had to match the case bore to the spigots. Good to here you can use a larger case bore with smaller sleeves. Is there a limit to size difference?

Fitting a stock block on bored cases is fine and all you need to do is not fit the 'O' rings on the bottom of the liners as they have nothing to sit against and you don't want them dropping into the crank .
Also when fitting larger liners or a big block etc you need to watch the length of the upper most mounting bolt of the ignition housing .
Depending on the liner size it will need shortening or it will hit the liner spigot and cause damage when tightened.

zed1015 wrote:

Mikaw wrote:

zed1015 wrote: If you really think you may go for re-sleeving at a later date then you should have the cases bored now to save the extra work and cost splitting the cases later.

This was another question, I wasn’t sure if you had to match the case bore to the spigots. Good to here you can use a larger case bore with smaller sleeves. Is there a limit to size difference?

Fitting a stock block on bored cases is fine and all you need to do is not fit the 'O' rings on the bottom of the liners as they have nothing to sit against and you don't want them dropping into the crank .
Also when fitting larger liners or a big block etc you need to watch the length of the upper most mounting bolt of the ignition housing .
Depending on the liner size it will need shortening or it will hit the liner spigot and cause damage when tightened.

There’s no replacement for experience. Thanks Zed1015

This seemed to be a good place to ask this as we are dissecting pros and cons of upsized pistons. I found a set of 1015 wiseco but they are 12.5 to 1. Any thoughts by the experts on the compression for a total street bike.

I am using a set of the same but using a J head to drop the comp to around 10 to 1.
Much more than 10.5 and detonation starts to become a problem and you will need to use the best fuel you can get so maybe you will need to use a block spacer.
0.5mm = approx 2 cc and drops around 1 point of compression.

That compression seems a bit high for a total street bike. My $0.02...

The highest pump octane we have here is 93. Then we jump to 110 turbo blue “race fuel” I guess you could mix it and keep tweaking it till you removed the dentonation with out hurting the wallet to bad...

Keep it up calum & post more pics as you progress. My Kawasaki was a jet black '77 KZ1000 just like yours. Very cool.