If I might ask is that with no major repairs?
No major repairs.
I keep RE at or below 60 mph for most of my rides. Sometimes it goes faster than that for short durations.
Once or twice in a year I get rid of 'cobwebs' in the engine by riding it between 70 to 80 mph for a few minutes
. I think that 'cleans' up engine and smooths out any rough edges.
I also make use of fuel additives or/and stabilizers as needed. I change engine oil frequently, every 2000 miles, because my older engine design does not drain oil completely. Newer models are better equipped to drain more oil, so they could last longer interval between oil change than mine.
Basically it is a good engine and if taken care of will last many years and many many miles. There are also others in India / Australia / and here who have over 20,000 miles - between 20K to 40K. Mine is not the only one.