Topic: kawasaki z650 piston

[bill hughes]

hi im just into building a track day bike a 77 cb 750 and want tofit kawasaki z650 pistons does any one know will there be any isues with
piston / valve im using a webb 41 cam
regards bill hughes

[livefast_dieold]

hi im just into building a track day bike a 77 cb 750 and want tofit kawasaki z650 pistons does any one know will there be any isues with
piston / valve im using a webb 41 cam
regards bill hughes

hi. I'm using the same pistons on my sohc for endurance races. No problem at all, valve clearance is about 2 mm (i'm using the same camshaft), compression ratio is 11.5:1 and displacement 760 cc. and they're 10 grams each lighter than stock pistons

[bucky katt]

is there ANY machining at all that needs to be done? pin diameter the same? anything have to be taken off of the skirts?

[livefast_dieold]

is there ANY machining at all that needs to be done? pin diameter the same? anything have to be taken off of the skirts?

none at all. Same pin diameter, some height of the pistons:

[KRONUS0100]

wait...what?  z650...as in KZ650?     what year?  i jus let a 75 model go to the scrappers yesterday.....arrrgg!!!

[bucky katt]

hmmmmmmmmmmmmmmmmmmmmmmm

[livefast_dieold]

kz650, i don't know year and model. It's the 2 valves for piston they made in the late '70.

BUT, be careful when installing the camshafts, I didn't double checked the distance between piston and valve after a tiny modification of the camshaft degreeing and the exaust valve hit the piston in all four cilinder after I missed a gear! 

[Terry in Australia]

That's good info, I bought a KZ650 big bore kit (65mm pistons, takes a KZ650 to 720cc) years ago, I used the rings on my 836cc engine, but the pistons are sitting in a box still, they might be better off in an F2 though, as the crowns sit a fair bit higher? With these, I reckon the compression ratio in a "K" engine would be closer to 15:1!  

[TCSOHCB750CAFE]

Any gains/issues from doing this piston swap on a CB750K with stock SOHC?

I've got a LOT of KZ650 engines in my garage, and just came across this thread and thought "well, hey... that kinda rules!"

[Hasenkopf]

that's funny... had i known that, I would'nt have got new rings for  my stockers !! :-

[75cb550 (kyle)]

Any gains/issues from doing this piston swap on a CB750K with stock SOHC?

I've got a LOT of KZ650 engines in my garage, and just came across this thread and thought "well, hey... that kinda rules!"

higher compression..

[TCSOHCB750CAFE]

I gathered that... I should have been more clear. Any clearance issues with stock cam?

[Retro Rocket]

Send forum member "Soos" a PM, he knows everything there is to know about these piston conversions and if i am correct, he has just done up a set of Kawasaki 650 pistons for another member....

http://forums.sohc4.net/index.php?topic=63523.50

Read reply 55 and on..

Soos modifies a range of pistons for these bikes.

Mick

[bill hughes]

hi i have now fitted kawasaki pistons to my 750 they fit ok just had to have the cylinders bored im running a web cam no problems with valve to piston have put in 125 main jets 4 into 1 ex at the moment it still on the bench but have run it at 6000 rpm and no problems ps how do i send pictures do i have to down size them

[kos]

Just for information. What is bore size of these pistons?

KOS

[turboguzzi]

hi im just into building a track day bike a 77 cb 750 and want tofit kawasaki z650 pistons does any one know will there be any isues with
piston / valve im using a webb 41 cam
regards bill hughes

hi. I'm using the same pistons on my sohc for endurance races. No problem at all, valve clearance is about 2 mm (i'm using the same camshaft), compression ratio is 11.5:1 and displacement 760 cc. and they're 10 grams each lighter than stock pistons

"using the same pistons on my sohc for endurance races"?

didnt see you in adria....

TG

[kos]

hi im just into building a track day bike a 77 cb 750 and want tofit kawasaki z650 pistons does any one know will there be any isues with
piston / valve im using a webb 41 cam
regards bill hughes

hi. I'm using the same pistons on my sohc for endurance races. No problem at all, valve clearance is about 2 mm (i'm using the same camshaft), compression ratio is 11.5:1 and displacement 760 cc. and they're 10 grams each lighter than stock pistons

What is bore size in mm's?

KOS

"using the same pistons on my sohc for endurance races"?

didnt see you in adria....

TG

[TCSOHCB750CAFE]

Just for information. What is bore size of these pistons?

KOS

62mm IIRC

[livefast_dieold]

hi im just into building a track day bike a 77 cb 750 and want tofit kawasaki z650 pistons does any one know will there be any isues with
piston / valve im using a webb 41 cam
regards bill hughes

hi. I'm using the same pistons on my sohc for endurance races. No problem at all, valve clearance is about 2 mm (i'm using the same camshaft), compression ratio is 11.5:1 and displacement 760 cc. and they're 10 grams each lighter than stock pistons

"using the same pistons on my sohc for endurance races"?

didnt see you in adria....

TG

I had to decline that race. The bike didn't need a lot of work, but the real life (aka: work and engineer state abilitation) destroy my free time. We will be in Rijeka however!

The pistons need some more valve clearance, they didn't like high revs; especially if you miss a gear.