I’ve came across a FR125 Rotax Sr. Engine that is need of a rebuild. Its pretty cheap but it looks like a bottom end rebuild would be $1400 by a shop. This also isn’t the most current model and I’m not even sure how to tell. Is it worth it to get this engine and rebuild it?
09 and newer got the new CNC barrel, clutch, metal balance gears, green coil, and air box. They have also updated the rad and pipe since then. If it doesn’t have those updates I wouldn’t even consider it.
By the time you rebuild it and do the updates you’re most of the way to a new engine or all the way to a gently used new spec.