How much can you bore an 850?

[850 Combat]

I beleive that Suzuki was racing a 920cc 750 in Superbike prior to racing the 1000 based bike. Possible that was in the class preceding Superbike.

[Chuck78]

The first Yoshimura GS race bike was a 944cc '77 GS750. Pops Yoshimura hand modified 73mm Honda pistons to fit the GS head. I believe they must have re-sleeved the block, as 72mm 920cc is the limit of what I'd feel comfortable with running reliably based on the thickness of the 850 sleeves after I bored them to 920cc.

Of course the Wiseco 844 69mm kit is approved to bore straight into the 65mm bore stock gs750 sleeves for +4mm overbore.