TOPIC:

My friend ( a fellow member on Kzrider) is having some issues with the piston rings on his 1977 Kz1000 LTD. We want to measure the bore of his cylinders and would like to have the exact factory specs to compare. It wouldn't hurt to also have the exact measurements of the first overbore for factory pistons.

Can anyone help with this question?

Cheers-Colin Firth-Ontario Canada
1977Kz650 Custom -810 big bore with lottsa go-fast goodies tucked hidden inside.

Now I'm not going to bet a months pay, but I'm pretty sure the standard bore for the 1000 engines is 70mm.
Hope this helps.

If Im reading the right part of the wiseco page, its 70mm(1015cc), the next size they list is 71mm(1045), then 72(1075) and 73(1105) to go bigger requires resleeving
link
not sure if the kaw oversized pistons follow the same jumps in size or not
Scott

Colin:

The manual states 70.0 (like inline4 said). Specifically, the manual lists 70.0 - 70.019 as standard with the service limit being 70.1

KZ 900 Bore / Stroke - 66 x 66 [mm]
KZ 1000 66 x 70 [mm]

OEM Pistons go in .5mm over size increments.

What's the problem with the ring end gap?

larrycavan wrote:

KZ 1000 66 x 70 [mm]

Should be 70 X 66.

vegasjetskier wrote:

larrycavan wrote:

KZ 1000 66 x 70 [mm]

Should be 70 X 66.

Yeah.. That 66 X 70 motor would be a KZ958:P

Jay

Yep...I was definitely not very awake this morning when I posted...I hate it when that happens...