‘76 KZ900 LTD. Need some advice.

The liners measure right at 8.5mm. EDIT: My bad, that should be 4.26mm, not 8.5

motomisfit wrote:

The liners measure right at 8.5mm. 

Do you mean cams at 8.5mm lift ?

No, the actual thickness of the liners.

motomisfit wrote:

No, the actual thickness of the liners.

So that makes the liner od 87mm not 78mm ? ( 70mm bore + 8.5mm x 2 )
That would make them capable of 1325cc bigbore which is impossible in a stock block casting.
Surely the measurements are wrong somwhere unless you measured at the liners top hat flange that sits in the barrel recess..

 

I’m sorry guys. This micrometer I’ve been using is going in the trash. My 0-1” is accurate. I just can’t use it on the bores obviously.
So .168 is about 4.26mm, knowing that this mic isn’t really the right one to use, but close enough for the sake of this conversation. I will edit my previous posts

motomisfit wrote:

I’m sorry guys. This micrometer I’ve been using is going in the trash. My 0-1” is accurate. I just can’t use it on the bores obviously.

So .168 is about 4.26mm, knowing that mic isn’t really the right one to use, but close enough for the sake of this conversation. I will edit my previous posts

Ok! So back to 78mm (ish) od on the liners. 
 

I’ll get a better ‘Vernier’ type micrometer tomorrow and confirm my numbers 

Wow what a bizarre combination. 1197 sleeves with stock 1015 pistons. I guess it could have been a budget issue. Once the sleeves were bought the PO could only afford to fit them in the block and bore the cases, but couldn’t afford the piston kit, and put stock in till he could replenish his budget. Nice to have the potential to go bigger. 

An accurate measurement will be needed to get you the correct base gasket. 

zed1015 wrote:

motomisfit wrote:

Ok! So back to 78mm (ish) od on the liners.  

Just a quick tip if you didn't already know, when measuring a curved surface with a micrometer - if your micrometer has flat anvils then you should add a ball bearing to the inside of the curve, then deduct the diameter of the ball bearing from your overall measurement as below

  

When I get a proper micrometer later today, I’ll post all measurements here on 1 post with pics so it’s not so scattered about.

Mikaw wrote:

Wow what a bizarre combination. 1197 sleeves with stock 1015 pistons. I guess it could have been a budget issue. Once the sleeves were bought the PO could only afford to fit them in the block and bore the cases, but couldn’t afford the piston kit, and put stock in till he could replenish his budget. Nice to have the potential to go bigger. 

An accurate measurement will be needed to get you the correct base gasket. 

And make sure I have a good return policy
 

Ok, that micrometer I was using is no longer with us.

I feel like a moron for making you all burn your brains with all my stupid numbers. These ARE indeed 66mm pistons and liners. The outside of the liner measures 74mm fwiw. At least now I know I can just get the stock size base and head gasket. Bike ran fine but I wasn’t able to do a CR test before I took the motor apart but I always figured I’d at least replace the rings while I was in there. It wasn’t burning oil. Hone the liners first for a little cleanup with new rings?

Measuring and doing the math again still tells me I only have about .314 lift on the intake cam. I thought even the factory cam lift was more than that.