TOPIC:

Just seen this. 
Those stains look like typical water/rust marking due to the engine being dormant a while, possibly with the plugs out..
The fact that they are on paired cylinders that share the same position on the crank throw suggest 1 and 4 were probably at the top of their bores which protected the liners whilst 2 and 3 were exposed.

Wookie58 wrote:

Looking positive Rolf, and you have "peace of mind" which is worth it's weight in gold 

Thats for sure  ! next now will be to see if i can get them back in

 

zed1015 wrote:

Just seen this. 
Those stains look like typical water/rust marking due to the engine being dormant a while, possibly with the plugs out..
The fact that they are on paired cylinders that share the same position on the crank throw suggest 1 and 4 were probably at the top of their bores which protected the liners whilst 2 and 3 were exposed.


I have been thinking of that water or fuel in cylinders theory too
 

Rolf1976_KZ900 wrote:

Wookie58 wrote:

Looking positive Rolf, and you have "peace of mind" which is worth it's weight in gold 

Thats for sure  ! next now will be to see if i can get them back in

 

Wait until your wife is out and "pop them in the freezer" 

That is what i did when installed new sleeves in my FJ

Did you cold press the sleeves out or warm the block.
Cold pressing can pull out material from the block and make the liners a loose fit.
The block should be heated to remove and install.
 

zed1015 wrote:

Did you cold press the sleeves out or warm the block.
Cold pressing can pull out material from the block and make the liners a loose fit.
The block should be heated to remove and install.


I have used an oven before ,but this time i just tried with an hot air dryer heated for 15 minutes and the sleeve almost fell out.The other sleeve was a little more difficult to get out but after some light tapping it came out.Today after i inspected them some more on outside i installed them by using the hairdryer and had the sleeves in the frezer only 15 minutes.I got problem with one of them that jammed so had to reheat and take it out and after a new attemt it got  in place


 

Well i messed up. I was finished with honing/deglaze the cylbores ,but i could still see some stripes in cyl 3 .I then tried to hone some more to remove the stripes in cyl 3.
The result was it got out of piston to cyl wall spec.It is now .010mm .I guess it can still work ,but not for thousands of kilometers and i want do do a proper job .
I have now ordered 4 new sleeves that will have to be bored out by a machine shop.they are ka765 sleeves has anybody installed that sleeve? 
Another thing ... why are the pistonrings for this bike so expensive??  at cmsnl  the rings for 1 piston has same price as 1 piston? i have searched for rings other places and they are
silly expensive.

IMD in the UK do rings that a lot of guys here are using, how does the cost of liners compare with "overboring" the originals ?

Motorbike Piston Ring Manufacturers UK & Online | IMD Pistons

Wookie58 wrote:

IMD in the UK do rings that a lot of guys here are using, how does the cost of liners compare with "overboring" the originals ?

Motorbike Piston Ring Manufacturers UK & Online | IMD Pistons

Hi and thanks for the link i have already been in contact with IMD  but did not ask if the rings they have will fit oem kawasaki pistons.

Im not 100% sure what to do yet but since i found the sleeves cheep about 86 GBP for 4 i just bought them.
the plan is to install the sleeves myself and send the barrels to a machine shop in another city in Norway
to get them bored and honed to fit  my oem pistons and skim the surface.I did that with my fj  in 2018 and the price was
 about 500 GBP for the machining work. Now it will be more expensive because the shop i used then is no longer in service.

i have several other options

1 buy oversized pistons and rings and get a shop to bore and hone the old sleeves i got

2 buy a complete set from IMD that has 4 pistons with the rings wristpins and clips and 4 sleeves,but that will have to get bored and honed and decked and it is not cheep here in Norway

3  i have spoken to IMD and they offer a complete barrel with new pistons and sleeves that is honed and ready to just install
that was expensive ,but so is machine work here in Norway.

Im not sure if the IMD pistonrings will fit oem kawasaki pistons ?

 

Since im waiting for sleeves  i finished the valves .i was hoping that i could just lap the exhaustvalves ,but the seats was to badly pitted and also seatface was to wide on them so had to use my neway cutter again.The valves was in better shape than the seats and none had bad deep pittings after lapping .After that i have bench shimmed the valves to check that non of the valvestems is to long after the seats was cut.If to long there is no space for shim and the valvestem must be grinded shorter.Not fun to discover that after the head is installed back in engine !
Im still curius if the KA765 sleeves i ordered will fit dont have any information about the measurements only that they will fit kz900
Going to buy pistonrings from IMD i think but need to ask if they will fit oem kawa pistons ?

Those KA765 sleeves are for boring up to 1290cc on a big block.
They are miles too big to fit a 900 block and theres not enough meat on the block to bore it out to fit them.
I'm pretty sure LA liners don't make the stock 900 replacement liners any more either.
The smallest they do is the stock z1000 ones ( KA 627) for 1015cc - 1075 cc  which will fit the 900 block if the alloy block is bored out or they will drop straight in a 1000 block.
These are the liners you need if you want stock 900 ones that drop straight in..
KAWASAKI Z900 KZ900 PISTON KITS (4) & CYLINDER LINERS (4) 66mm | eBay