Direct bolt-on >>> no.
The csr tank has a rear mounting tab that points straight down, so it's 90o off from the KZ700.
Do you have a 700 tank to measure? for comparison to a csr tank. in case it can be adjusted to fit.
I'm pretty sure the 82 GPz 750-R1 & 83 750-L3 tanks will fit the KZ700.
Also, probably the L1-L4 models sold in the UK & maybe the GT750s sold in the UK.
