Out of all the questions I get regarding upgrading a Katana, one of the top ten must be "will a Gs1100 engine fit into my Gs750?" The short answer is yes. The long answer is also yes.

Another one is the old "how can I get more power out of my 750 katana?" Well, the biggest bang for the buck is an 1100. For the cost of a piston kit and cams you can bolt in an 1100 and be way ahead on HP with tons of room to move forward into the stupid fast realm (if you are so inclined)

There are only a couple issues with the 1100 install that I will lay out here.

First, you have to find an 1100 engine. Getting harder all the time.
Second, the Gs1100 bolts right into your Katana. four of the six motor mounts line right up. The ones that do not are the lower mounts. On the Gs750 the mounts are approximately one inch too far back for the Gs1100 cases which is easily rectified by a new set of lower mounts that you can make yourself or buy from this site.

The next issue to consider is the gearing differential in the 1100 engine compared to the 750. The 1100 Katana uses a 17" wheel and the 750 Katana has an 18" rear wheel.

What does that mean? Well, the 750 Katana also has a 15 tooth front sprocket where as the 1100 has a 14 tooth. The 1100 Katana has a 42 tooth rear sprocket and the 750 Katana has a 43. So, I would use the 1100 engines 14 tooth sprocket and look for a larger rear. Ideally you want to move to a 530 chain and lose about 8 lbs of turning steel.

If you are wanting to do a 530 conversion have  a look at the info HERE

Other than that there is the tachometer redline difference of 500 rpm. No biggie, the 1100 can handle it.

One last thing, the oil pressure  light wire length may need to be addressed and that's about it. Oh yes, don't forget to get some new grips cuz you'll be using them now.