I have much experience with automobile engine build-ups, especially Chevy small block engines. I have bored and stroked them to various sizes. I presently own a 1981 Yamaha RH 920. It is chain drive, not shaft drive like the 1100 Virago. I have found that when you swap the crank you also need to swap the rods and pistons or the longer stroke may cause interference with the head. At least this is the way with auto engines. You need a piston that will accomodate the longer stroke. So, relying on my experience, I would say that in order to make the 920 into an 1100 you would need to swap the crankshaft, connecting rods and pistons and cylinders together. If using the 920 heads, the increase in bore size from 920 to 1100 will also raise compression. Personally, I would just go to 1000cc by using cylinders and pistons from a 1000cc Virago and do some mild head porting and a 3 angle valve job for increased flow. The only difference between a 1000cc and a 1100 is stroke. The 1000cc and 1100cc have the same bore size. The longer stroke will not rev as quickly, but you also will not need to turn it as high to build the same torque. I hope this helps.

i would love to make my virago have more power and what im reading about the 1000cc cylinders and pistons in place of the 920s is great but i cant find the 1000cc cylinders the pistons and rings are available from yamaha still but not the cylinders does anyone have any and if so how much.................bigfoot