DonPearsall

If you go faster than the record speed you must have your bore and stroke measured. On my Hayabusa that was fairly easy because they have a device that can measure both through the spark plug holes. The 'Busa has centered straight plug holes. But the GS1000 has angled holes so that is not possible. You must take off the head and get it measured that way. It is a real hassle. But you can't break a record unless that is done.

Has anyone here measured the combustion chamber volume on the GS1000 engine? I need that info for compression ratio calcs. Is there a reference for this? Thanks Don

Thanks for the reply. Yes, land speed racing in the stock class so can't go over 1000cc. I will do a search for Yoshimura. Don

I have a 1979 GS1000E. I want to increase the compression ratio from the stock 9.2 CR to about 11.0 but want to keep the stock 70mm bore. I have looked and looked online and can't find any kits that will do this. I know there are lots of overbore kits, but need to keep the displacement under 1000cc. All overbore kits take the displacement over 1000cc. Does anyone know of a kit that will do this? Alternatively I can mill the head, but that is the last choice. Has anyone milled their GS1000 or 1100 head? Thanks, Don