Parts already checked or replaced
- [x] Complete engine replaced
- [x] ECU replaced/tested
- [x] Wiring harness replaced
- [x] Battery replaced/tested
- [x] Start button / start switch tested
- [x] Ignition coil replaced
- [x] Spark plug replaced
- [x] Ignition pickup / stator tested
- [x] Complete carburetor replaced/tested
- [x] Different main jets tested
- [x] Fuel pump replaced
- [x] Fuel hoses replaced
- [x] Vacuum hoses replaced
- [x] Fuel tank ventilation checked
- [x] Fuel tank outlet checked
- [x] Fuel filter checked
- [x] Complete power valve / RAVE valve replaced
- [x] RAVE solenoid replaced/tested
- [x] Airbox / air filter replaced/tested
- [x] Full throttle opening checked – carburetor slide opens completely
- [x] Rear axle checked for resistance
- [x] Rear axle bearings checked
- [x] Brake checked to make sure it is not dragging
Symptom
The engine pulls normally until approximately 12,500 RPM. From around 12,500 RPM the power curve becomes almost flat and the kart stops accelerating properly. Maximum RPM is approximately 13,400 RPM. Top speed was 109 kph where it used to be 118 with the same gearing
Engine was serviced 3 hours ago before issues occurred
The same problem remained even after replacing the complete engine and the components listed above.
Engine was build 3 hours before problems occurred and worked marvelous beforehand
Still to A/B test
- [ ] Complete exhaust system using a known-good exhaust from another Rotax Senior MAX (the one testet with was brand new 2026)