R50 to R75 conversion

[Raceydog]

Ok. The time has come to start working on the 1972 R50/5. One thing I have planned to do is convert it to a R75. Anyone know what parts I need to do it? I am guessing I will need pistons and heads. Any input will really help.
Jimmy

[Wrong Way]

The bottom end of that engine is the same for both a R50/5 and an R75/5. You will need new cylinder barrels (or bore the olds ones), heads, and pistons and rings. You may be able to have the R50 barrles bored to accomadate the bigger pistons. That year of bike has a cast iron sleeve that should allow that. Everything else in the drive train is the same.