I am in the process of replacing the rings on my 900 and they were stamped
.070 over. I ordered a set and to my surprise, they were way to small. I took one of the cyliners to the local dealer and after measuring the bore, I found out I had 1000 jugs on my motor. I had no idea that this was even possible. In any event, has anyone else have this situation? Would they be the original heads? Is there a large performance increase over stock? Is it possible to go back to stock equipment or did it require modifying the block?
Dytch used to make 3"3/16 jugs (and pistons...) for old 900 from the early 60's. Normally the cyls are cast marked "Front" and "Rear" on the left hand side. They needed the crankcase cyl bores enlarged obviously.
These were std height and usually for use with stocker pistons.
So check your stroke as well!!!
The 900 heads needed machining to fit on the Dytch cyls and use bigger head gaskets. The 1000 OEM gasket can be made to fit these, otherwise, trim some 900 head gaskets to suit.