Identify these Yoshimura pistons "POPY" PIX ADDED

pistons, pins, retainers. bought years ago for a project and i only wrote kz900/1100 on the box when i put them in the closet. 73mm, one side has the yoshi symbol the other has the "popy" sig i think. only other marking on them is a symbol on the inside of one of the skirts. pix show this. and how much a work of art these things look like. any help is appreciated and have fun hopefully!! today i got a guys email from yoshi japan so i can send him the pix also. oh, the popy is on one side by the pin and the yoshi is on the other. both to the lower left when looking at it. thanks alot for any input.

well it wouldn't take my pix? PIX COMING

they are pops yosh pistons from when they were building kaw superbikes....they had several "kits" available....
stage 1 to 4
i have a buch of literature here somewhere....they are probably 1015 slipper pistons....

ill try and post some info tomorrow

BTW....I have a complete yosh motor with carbs and close ratio trans....ect,ect very cool stuff

they have a very high dome with large reliefs for the valves and are gas ported. my pix have too many pixels, i will try to make them smaller some how. thanks

yeah that is cool on the yosh motor. i don't know how much stuff they made. i heard of the rods and heads besides pistons and cams.

irishwill wrote:

they are pops yosh pistons from when they were building kaw superbikes....they had several "kits" available....
stage 1 to 4
i have a buch of literature here somewhere....they are probably 1015 slipper pistons....

ill try and post some info tomorrow

BTW....I have a complete yosh motor with carbs and close ratio trans....ect,ect very cool stuff

Yea, They had great stuff and was the hot set-up before Pops went to the Suzuki. The shop I was at in the 70's did alot of 987's and they where fast!

hope you enjoy it

Totally awesome stuff, thanks alot!! i am pretty clueless really. just had alot of kz's and a few gpz's over the years and know how to work on em stock anyways, seems like i forgot everything about modin em. finally got my pix on here. figuring these are for 73 to 81 engines but not sure of a few things like if they are for a 900 only or if the 1000 just had a bigger stroke and the same size cylinders, that and the compression ratio of these pistons. i need to find a chart showing me some info on cylinder sizes etc. is there any info out there on the current value of an n.o.s set like this?? i have alot to learn about modifyin' em. i don't have a clue how far you can bore out 900's or 1000's etc. i have a big bore cylinder with 12.1? wiesco's sitting here that i think i am gonna use on my z1. thanks again