Fat Duc O2 Emulator For Many Aprilia, Moto Guzzi, and Vespa models *See detailed fitment list*
Availability: In stock -- Ready to Ship Now!
SKU: FD02M-1
$92.99 (USD)

Fat Duc O2 Emulator

All models require quantity 1 unless noted otherwise below:

For Aprilia:

  • Shiver 900 (quantity 2 required)
  • Dorsoduro 900 (quantity 2 required)
  • CapoNord 1200 (quantity 2 required)
  • Caponord 1200 Rally (quantity 2 required)

For Moto Guzzi:

  • V85 TT (all variants) [requires quantity 2]
  • Norge 1200 (requires quantity 2)
  • Stelvio NTX 1200 8V ABS (requires quantity 2)
  • '13-'15 V7 Racer (requires quantity 2)
  • V7 Racer II (requires quantity 2)
  • V7 III Racer (requires quantity 2)
  • V7 Stone (requires quantity 2)
  • V7 Stone II (requires quantity 2)
  • V7 III Stone (requires quantity 2)
  • V7 Special (requires quantity 2)
  • V7 Special II (requires quantity 2)
  • V7 III Special (requires quantity 2)
  • V7 Stornello (requires quantity 2)
  • V7 III Anniversario (requires quantity 2)
  • V7 III Rough (requires quantity 2)
  • V7 III Milano (requires quantity 2)
  • V7 III Carbon Shine (requires quantity 2)
  • V7 III Carbon Dark (requires quantity 2)
  • V9 Bobber (requires quantity 2)
  • V9 Roamer (requires quantity 2)
  • MGX 21 (requires quantity 2)
  • California 1400 Touring (requires quantity 2)
  • California 1400 Custom (requires quantity 2)
  • Eldorado 1400 (requires quantity 2)
  • Audace 1400 (requires quantity 2)

FatDuc is a means of richening the part throttle fuel mixture on certain Aprilia/Moto Guzzi/Vespa models specifically the Aprilia Shiver and Dorsoduro 750/1200. This unit fits all models listed above, but extensive, successful testing has been carried out only on the Shiver and Dorsoduro 750/1200 models.

The reason your bike suffers from poor fuel economy and throttle response is emissions mandated lean fueling, also the cause of the extreme heat coming from the exhaust system and very hot running in town, this device SIMPLY plugs inline with the stock oxygen sensor and allows a small reduction in the voltage of the return signal to the ECU, which richens the mixture. This results in improved throttle response, fuel economy (I know this seems contradictory) and smoother running at cruise.

There is NO full throttle power gain to be expected since it does not alter wide open throttle fueling. The difference when riding the bike however is night and day, AND the device is adjustable.

You CANNOT make the motor run leaner with this mod anywhere in the rpm range but it is adjustable from an effective zero change from stock to very rich, we recommend you try the "as delivered” setting on the trip screw first and make only very small adjustments from there.

Full installation instructions, as provided by FatDuc are available as a .pdf download at the link below:

FatDuc Emulator Instructions

An illustrated instruction guide for the Dorsoduro 750 can be found on our forum at this link


Products specifications
20132015ApriliaRSV4 Factory APRC ABS
20132015ApriliaRSV4 R APRC ABS
20112012ApriliaRSV4-R APRC
20112012ApriliaRSV4 Factory APRC
20092010ApriliaRSV4 Factory
20162016ApriliaTuono V4 1100 RR
20162016ApriliaTuono V4 1100 Factory
20142015ApriliaTuono V4 ABS
20112013ApriliaTuono V4
20162017ApriliaCaponord 1200 Rally
20142017ApriliaCaponord 1200 Travel Pack
20082015ApriliaMana GT/Mana
20182021ApriliaDorsoduro 900
20152016ApriliaDorsoduro 750
20092014ApriliaDorsoduro 750
20112012ApriliaDorsoduro 1200
20192020ApriliaShiver 900 Navi
20182019ApriliaShiver 900
20152016ApriliaShiver 750
20112014ApriliaShiver 750
20072010ApriliaShiver 750
20082012ApriliaSportCity Cube 250/300
20062008ApriliaSportCity 250
20192020Moto GuzziV85 TT Adventure
20192020Moto GuzziV85 TT Travel
20202020Moto GuzziV7 III Stone S
20202020Moto GuzziV7 III Racer 10th Anniversary
20192020Moto GuzziV7 III Stone Night Pack
20192020Moto GuzziV7 III Special
20192020Moto GuzziV7 Racer Limited (White Tank)
20182018Moto GuzziV7 III Milano
20182018Moto GuzziV7 III Carbon Shine
20182018Moto GuzziV7 III Carbon Dark
20182018Moto GuzziV7 III Rough
20172020Moto GuzziV7 III Stone
20172020Moto GuzziV7 III Special
20172020Moto GuzziV7 III Racer
20172017Moto GuzziV7 III Anniversario
20162016Moto GuzziV7 Stornello II
20162016Moto GuzziV7 Stone II
20162016Moto GuzziV7 Special II
20162016Moto GuzziV7 Racer II
20142015Moto GuzziV7 Stone
20142015Moto GuzziV7 Special
20132015Moto GuzziV7 Racer
20132013Moto GuzziV7 Stone/Special
20192020Moto GuzziV9 Roamer
20192020Moto GuzziV9 Bobber Sport
20192020Moto GuzziV9 Bobber
20172018Moto GuzziV9 Roamer
20172018Moto GuzziV9 Bobber
20102016Moto GuzziNorge 1200 8V
20122017Moto GuzziStelvio NTX ABS
20172020Moto GuzziCalifornia 1400 Touring
20132016Moto GuzziCalifornia 1400 Touring
20132016Moto GuzziCalifornia 1400 Custom
20172019Moto GuzziEldorado 1400
20162016Moto GuzziEldorado 1400
20162018Moto GuzziMGX 21
20172018Moto GuzziAudace 1400
20162016Moto GuzziAudace 1400
20212022VespaGTS 300 HPE Super Sport
20182022VespaGTS 300 HPE Super
20182021VespaGTS 300 HPE
20142017VespaGTS 300 ABS, GTS 300 Super ABS
20142017VespaGTS 300 ABS
20142017VespaGTS 300 Super ABS
20102014VespaGTS 300
20082010VespaGTS 250 Super
20052010VespaGTS 250, GTS 250 Super
20052010VespaGTS 250
20192021VespaGTV 300 Sei Giorni HPE
20182018VespaGTV 300 Sei Giorni
20162017VespaGTV 300 ABS
20102015VespaGTV 300
20072010VespaGTV 250
20232024VespaPrimavera 150 Mickey
20172023VespaPrimavera 150 iGet
20192024VespaPrimavera 50 ie (Fuel Injected)
20232023VespaPrimavera 50 Mickey Mouse
20172023VespaSprint 150 iGet
20222023VespaSprint 150 Bieber
20192023VespaSprint 50 ie (Fuel Injected)
20112016VespaLXV 150 ie (Fuel Injected)
20102014VespaLX 150 ie (Fuel Injected)
20112014VespaS 150 ie (Fuel Injected)
20082010PiaggioBV250 (Headlight on Handlebar)
20062009PiaggioBV250 (Headlight in Fairing)
20102014PiaggioMP3 250
20062012PiaggioMP3 250
20072009PiaggioMP3 250
20242024PiaggioLiberty 150 (all variants)
20182023PiaggioLiberty 150 (all variants)
20242024PiaggioLiberty 50 (all variants)
20182023PiaggioLiberty 50 USA (all variants)
Products specifications
Year/Make/Model2013-2015 Aprilia RSV4 Factory APRC ABS
Year/Make/Model2013-2015 Aprilia RSV4 R APRC ABS
Year/Make/Model2011-2012 Aprilia RSV4R APRC
Year/Make/Model2011-2012 Aprilia RSV4 Factory APRC
Year/Make/Model2009-2010 Aprilia RSV4-R
Year/Make/Model2009-2010 Aprilia RSV4 Factory
Year/Make/Model2016 Aprilia Tuono V4 1100 RR
Year/Make/Model2016 Aprilia Tuono V4 1100 Factory
Year/Make/Model2014-2015 Aprilia Tuono V4 ABS
Year/Make/Model2011-2013 Aprilia Tuono V4
Year/Make/Model2016-2017 Aprilia Caponord 1200 Rally
Year/Make/Model2014-2017 Aprilia Caponord 1200 Travel Pack
Year/Make/Model2008-2015 Aprilia Mana GT/Mana
Year/Make/Model2018-2021 Aprilia Dorsoduro 900
Year/Make/Model2015-2016 Aprilia Dorsoduro 750
Year/Make/Model2009-2014 Aprilia Dorsoduro 750
Year/Make/Model2011-2012 Aprilia Dorsoduro 1200
Year/Make/Model2019-2020 Aprilia Shiver 900 Navi
Year/Make/Model2018-2019 Aprilia Shiver 900
Year/Make/Model2015-2016 Aprilia Shiver 750
Year/Make/Model2011-2014 Aprilia Shiver 750
Year/Make/Model2007-2010 Aprilia Shiver 750
Year/Make/Model2008-2012 Aprilia SportCity Cube 250/300
Year/Make/Model2006-2008 Aprilia SportCity 250
Year/Make/Model2019-2020 Moto Guzzi V85 TT Adventure
Year/Make/Model2019-2020 Moto Guzzi V85 TT Travel
Year/Make/Model2020 Moto Guzzi V7 III Stone S
Year/Make/Model2020 Moto Guzzi V7 III Racer 10th Anniversary
Year/Make/Model2019-2020 Moto Guzzi V7 III Stone Night Pack
Year/Make/Model2019-2020 Moto Guzzi V7 III Special
Year/Make/Model2019-2020 Moto Guzzi V7 Racer Limited (White Tank)
Year/Make/Model2018 Moto Guzzi V7 III Milano
Year/Make/Model2018 Moto Guzzi V7 III Carbon Shine
Year/Make/Model2018 Moto Guzzi V7 III Carbon Dark
Year/Make/Model2018 Moto Guzzi V7 III Rough
Year/Make/Model2017-2020 Moto Guzzi V7 III Stone
Year/Make/Model2017-2020 Moto Guzzi V7 III Special
Year/Make/Model2017-2020 Moto Guzzi V7 III Racer
Year/Make/Model2017 Moto Guzzi V7 III Anniversario
Year/Make/Model2016-2016 Moto Guzzi V7 Stornello II
Year/Make/Model2016-2016 Moto Guzzi V7 Stone II
Year/Make/Model2016-2016 Moto Guzzi V7 Special II
Year/Make/Model2016-2016 Moto Guzzi V7 Racer II
Year/Make/Model2014-2015 Moto Guzzi V7 Stone
Year/Make/Model2014-2015 Moto Guzzi V7 Special
Year/Make/Model2013-2015 Moto Guzzi V7 Racer
Year/Make/Model2013 Moto Guzzi V7 Stone/Special
Year/Make/Model2019-2020 Moto Guzzi V9 Roamer
Year/Make/Model2019-2020 Moto Guzzi V9 Bobber Sport
Year/Make/Model2019-2020 Moto Guzzi V9 Bobber
Year/Make/Model2017-2018 Moto Guzzi V9 Roamer
Year/Make/Model2017-2018 Moto Guzzi V9 Bobber
Year/Make/Model2010-2016 Moto Guzzi Norge 1200 8V
Year/Make/Model2012-2017 Moto Guzzi Stelvio NTX ABS
Year/Make/Model2017-2020 Moto Guzzi California 1400 Touring
Year/Make/Model2013-2016 Moto Guzzi California 1400 Touring
Year/Make/Model2013-2016 Moto Guzzi California 1400 Custom
Year/Make/Model2017-2019 Moto Guzzi Eldorado
Year/Make/Model2016-2016 Moto Guzzi Eldorado 1400
Year/Make/Model2016-2018 Moto Guzzi MGX 21
Year/Make/Model2017-2018 Moto Guzzi Audace 1400
Year/Make/Model2016-2016 Moto Guzzi Audace 1400
Year/Make/Model2021-2022 Vespa GTS 300 HPE Super Sport
Year/Make/Model2018-2022 Vespa GTS 300 HPE Super
Year/Make/Model2018-2021 Vespa GTS 300 HPE
Year/Make/Model2014-2017 Vespa GTS 300 ABS, GTS 300 Super ABS
Year/Make/Model2014-2017 Vespa GTS 300 ABS
Year/Make/Model2014-2017 Vespa GTS 300 Super ABS
Year/Make/Model2010-2014 Vespa GTS 300
Year/Make/Model2008-2010 Vespa GTS 250 Super
Year/Make/Model2005-2010 Vespa GTS 250, GTS 250 Super
Year/Make/Model2005-2010 Vespa GTS 250
Year/Make/Model2019-2021 Vespa GTV 300 Sei Giorni HPE
Year/Make/Model2018-2018 Vespa GTV 300 Sei Giorni
Year/Make/Model2016-2017 Vespa GTV 300 ABS
Year/Make/Model2010-2015 Vespa GTV 300
Year/Make/Model2007-2010 Vespa GTV 250
Year/Make/Model2023-2024 Vespa Primavera 150 Mickey
Year/Make/Model2017-2023 Vespa Primavera 150 iGet
Year/Make/Model2019-2024 Vespa Primavera 50 ie (Fuel Injected)
Year/Make/Model2023 Vespa Primavera 50 Mickey Mouse
Year/Make/Model2017-2023 Vespa Sprint 150 iGet
Year/Make/Model2022-2023 Vespa Sprint 150 Bieber
Year/Make/Model2019-2023 Vespa Sprint 50 ie (Fuel Injected)
Year/Make/Model2011-2016 Vespa LXV 150 ie (Fuel Injected)
Year/Make/Model2010-2014 Vespa LX 150 ie (Fuel Injected)
Year/Make/Model2011-2014 Vespa S 150 ie (Fuel Injected)
Year/Make/Model2009-2012 Piaggio BV300
Year/Make/Model2008-2010 Piaggio BV250 (Headlight on Handlebar)
Year/Make/Model2006-2009 Piaggio BV250 (Headlight in Fairing)
Year/Make/Model2010-2014 Piaggio MP3 250
Year/Make/Model2006-2012 Piaggio MP3 250
Year/Make/Model2007-2009 Piaggio MP3 250
Year/Make/Model2024 Piaggio Liberty 150 (all variants)
Year/Make/Model2018-2023 Piaggio Liberty 150 (all variants)
Year/Make/Model2024 Piaggio Liberty 50 (all variants)
Year/Make/Model2018-2023 Piaggio Liberty 50 USA (all variants)
Product tags