If it was mine I would re-power when in good condition. Some of the ride-ons coming out now for the homeowner are not as good as the older stuff. Later models did used the 310000 series Briggs OHV.
I got an older 2005 Bolens (MTD) that out cuts most of the newer equipment customers bring in for repairs here. I have had mowers in here that couldn't even cut lightly over grown lawns as they were so under powered. This the case for 2009 Bolens model the engine is about 2 hp short as it tries to stall out when cutting grass. No way it would cut that 12+ inch grass that 05 does. Main difference between the two is the 05 has 15.5 hp with 38" cut and the 09 has 16.5 Hp with 42" cut.
