Deere 4X20 upgrades in 2009

[MaximizerMatt]

Noticed on TractorData.com that there was a break in the 4X20 series compacts from 2008 to 2009. According to Tractordata's info on the 4720, "For the 2009 model year (tractor serial number 650001), the John Deere 4720 was upgraded with the eThrottle feature, increased engine power, and an optional 540e PTO." My question is this: does anyone know if the horsepower bump was electronic or a physical change to the engine? Could older units be "programmed" with the higher horsepower, either by a dealer, or aftermarket supplier? Just curious.

Thanks,
Matthew

 

[arlen4720]

Noticed on TractorData.com that there was a break in the 4X20 series compacts from 2008 to 2009. According to Tractordata's info on the 4720, "For the 2009 model year (tractor serial number 650001), the John Deere 4720 was upgraded with the eThrottle feature, increased engine power, and an optional 540e PTO." My question is this: does anyone know if the horsepower bump was electronic or a physical change to the engine? Could older units be "programmed" with the higher horsepower, either by a dealer, or aftermarket supplier? Just curious.

Thanks,
Matthew

The fuel system was completely revamped as part of the change. If you probe around on JDparts.com you can see the changes.
Basically, they went from a mechanically governed engine to a full authority electronically controlled fuel injection system.
The computer, governor, and injectors are all different.