You fall off the SuperJet, it rolls, you right it, and now the starter turns or does nothing and the engine won't run. This concerns the four-stroke SuperJet from 2021, the stand-up with the 1049 cc three-cylinder TR-1 engine. It has no reverse and no RiDE, which makes the electrical side comparatively simple.
Switching off on purpose
The SuperJet has a slant switch that cuts the engine when the boat tips over, so the engine stopping on the capsize is the design working. The control unit knows this as code 47 (slant switch) in the newer generation of units, so finding a 47 in the memory after a capsize is nothing to worry about. What matters is whether it is active again after you have righted the boat.
The switch states in the live data should include the slant switch. With the boat upright it should read as normal. If it still reads tipped, the switch or its connector is the issue, and the engine will stay off. Code numbers can differ by control unit generation and by source, so go by the description in the app.
What to check, in this order
- The lanyard. In a fall the kill switch cord is pulled, and it is easy to put it back not quite seated. Check that it sits fully before anything else.
- Read the fault memory, note the entries, and clear it. If 47 returns immediately while the boat is level, the switch is the suspect.
- Battery voltage. Look at the voltage at rest and while cranking. A pronounced dip under the starter points to the battery or its terminals before anything else.
- Wet connectors. Saltwater and freshwater both creep into plugs when the boat is upside down. Open the connectors you can reach, dry them and reseat them.
- The individual tests, if the engine cranks but won't catch: the three coils, the three injectors and the fuel pump, seven components in all. A pump test shows only that the pump runs.
The question the app can't answer
If the boat was down for a while with the intake open to the water, the engine may have taken water in. The app can't see that. Cranking over and over is not a good idea when you suspect it, because that becomes a mechanical question and not an electronic one. Likewise, corroded plugs that cause trouble without a stored code won't appear in the data.
If the coils and injectors all respond and the pump runs, the electrical side is in reasonable shape, and the remaining question is water or fuel. That narrows the field a lot, even though it doesn't name the culprit.
When you try tests with the engine running on land, make sure water is supplied to the cooling system. When anything touches the fuel system, work with good ventilation and no ignition sources nearby.
Where the app helps
The M-JET Diagnostic supports the four-stroke SuperJet and shows the slant switch, the battery voltage and the switch states live. It runs the individual coil and injector tests and the pump test from the phone, so you can see which cylinder is missing without pulling anything apart. The SuperJet is also described on the SuperJet diagnostics page, and the general no-start sequence is on the won't start page.
One more thing worth knowing: the learner mode, L-Mode, limits power on purpose. If the engine runs but feels weak after you get going again, check that mode before assuming something broke.
