A used supercharged Yamaha from 2009 to 2016 or a FX SVHO that ran until 2023 carries three questions a buyer has to answer: the supercharger clutch, the timing chain and how hard the hours were. A scan helps with two of them, and it is better to know up front which two.
Which skis, which years
The FZR and FZS (SHO engine) were built from 2009 to 2016. The FX SHO, FX SVHO and Cruiser SVHO ran from 2012 to 2023, the GP1800R SVHO from 2017. All are 1.8 litre engines with a supercharger. The M-JET Diagnostic supports them, and the pages on FZR and FZS and SVHO and SHO go into the models.
The supercharger clutch
Early SHO skis from 2009 to 2013 had known clutch trouble at the supercharger, and Yamaha reworked it later. Owners across several models describe the same symptoms when the clutch is worn: the engine runs cleanly, but on the water it hangs at around 5000 to 5500 rpm, power falls away beyond roughly 6000, and intake pressure stays close to ambient where it should climb. Owners also say that checking the clutch by hand is unreliable, so a clutch that feels fine on the bench proves little.
This is where a scan earns its place. Intake pressure is a live value, and a test ride with the logger on will show whether it builds with throttle and rpm or sits near the air pressure reading. If it never builds, you have a lead. What the scan can't do is prove the supercharger or the clutch is the cause, since other faults can produce a similar picture, and it can't say how long a clutch has left.
The timing chain
The SVHO of 2014 and 2015 has a weak chain according to many reports, and from 2016 it was strengthened. That makes the model year more important than the hours. No diagnostic tool can see chain wear, this app included. A ski from those two years should have documentation of what was done to the chain, or the engine should be looked at by a mechanic who knows it, before money changes hands. A clean scan means nothing here.
How hard were the hours
The control unit stores engine hours and the hours per rpm band. Read the bands and look at the top ones. A supercharged ski with many hours at the upper end of the range has lived with a lot of heat and load, which is worth knowing even if nothing is broken today. Heat soak from the supercharging is real, and owners report it. Read the page on hours in the high rpm range for how to interpret it.
Order of the check
- Model year first. 2014 and 2015 SVHO get the chain question, 2009 to 2013 SHO the clutch question.
- Fault memory, written down, nothing cleared.
- Hours total and per band.
- Test ride with the logger, watching intake pressure, intake air temperature, engine temperature and rpm together.
- Component tests on coils, injectors and pump, with the usual fuel safety in mind.
If the ski hangs at 5000 to 5500 rpm with no boost, walk away or factor the repair into your offer. If the logged ride looks right, the chain remains the question that only a mechanic can settle.
