Sea-Doo 300 HP vs. 325 HP – ECU, Tuning and What Really Differs
Two power levels dominate the Sea-Doo lineup: 300 HP and 325 HP. Both share the same Rotax 1630 ACE engine with supercharger – yet the differences go well beyond just the numbers, especially when it comes to ECU, tuning access and the M-JET FLASHER product lineup.
Same Engine – Different Technology
| Sea-Doo 300 HP | Sea-Doo 325 HP | |
|---|---|---|
| Engine | Rotax 1630 ACE | Rotax 1630 ACE |
| Displacement | 1630 cc | 1630 cc |
| Forced induction | Supercharger | Supercharger |
| ECU | Bosch ME17.8.5 | Bosch MG1CA920 |
| GPS/Vmax speed limit | No | Yes (factory) |
| Tuning without unlock | Yes | No |
| ECU unlock required for tuning | No | Yes |
| Models | RXP-X 300, RXT-X 300, GTX 300 (until 2023) | RXP-X 325, RXT-X 325, GTX Limited 325 (from 2024) |
The 300 HP: Bosch ME17.8.5 – Ready to Tune Right Away
The 300 HP models run on the Bosch ME17.8.5 ECU – maximum flexibility without any preliminary step:
- M-JET FLASHER for RXP-X / RXT-X 300 – tune directly, no unlock needed
- M-JET FLASHER for GTX 300 – ready to go straight away
- M-JET FLASHER for GTX 230/300 (2018–2024) – fully supported
- M-JET DIAGNOSTIC – fault codes, live data including boost pressure, service functions
- No factory GPS speed limit
The 325 HP: Bosch MG1CA920 – More Power, New Possibilities
The 325 HP models come with the newer Bosch MG1CA920 ECU. The following works immediately – without any unlock:
- M-JET DIAGNOSTIC – diagnostics, fault codes, live data – Plug & Play
- M-JET Vmax Remover – removes the factory GPS/Vmax speed limit on RXP-X 325, RXT-X 325 and GTX Limited 325 – no power change, activate via app
For real performance tuning on the 325: first complete the one-time ECU Unlock for Sea-Doo 325 – after that all tuning stages are available with the M-JET FLASHER.
All Sea-Doo Models and Their Tuning Options
| Model | ECU | Tuning |
|---|---|---|
| Sea-Doo Spark & Spark Trixx (2014–2026) | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo GTI (2014–2021) | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo GTX 130 / 170 | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo Wake 170 | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo Wake Pro 230 | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo GTX 230 / 300 (2018–2024) | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo RXP-X / RXT-X 300 (2016–2023) | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo GTX 300 (2016–2023) | ME17.8.5 | M-JET FLASHER – direct |
| Sea-Doo RXP-X / RXT-X / GTX Limited 325 | MG1CA920 | ECU Unlock → M-JET FLASHER |
Which Path Is Right for You?
Got a 300 HP and want to tune? Head straight to the M-JET FLASHER – no preliminary step needed.
Got a 325 HP and just want the speed limit removed? M-JET Vmax Remover – Plug & Play, no unlock, reversible.
Got a 325 HP and want real performance tuning? Start with the ECU Unlock – then all stages are open with the M-JET FLASHER.
Just want to keep an eye on engine health? M-JET DIAGNOSTIC – works on both 300 and 325 models without unlock.
Extras for All Sea-Doo Models
M-JET Temperature Module – Oil or water temperature directly in the display, from MY 2018, Plug & Play
M-JET Auto-Sport Module – Automatically in Sport Mode after every start
M-JET CTEK Charging Adapter – Maintenance charging of the battery via the original Tow Pylon socket
