advice needed!!

Hello all,

I currently have an r850rt 53 reg (ex police) and need a new engine. my mechanic (which i have not used before) has said i can fit an 1100 engine onto the bike if i wanted to...
is this true and is there anything else that would need to be done to the bike to convert it fro an 850 to an 1100 ?

many thanks in advance.

Hi, as far as I'm aware that is a straight bolt on. Cases are the same for engine and gearbox.

Thought the diff final drive ratio was different between the 850 and 1100