OS engines have been around for a long time and have proven to be top notch mills with IMO the best carbs in the business. The new On Road XZR is no exception and IMHO is a score. It's a vast improvement from there old ZVR that's for sure. If properly maintained "rod/bearings changed as needed and tuned properly" should live a good long life! The one thing i would have really liked to see on the 21XZR would be DLC coating on the crankshaft....

The whole new XZ line from OS has been great so far and has yet to disappoint.