I can explain a Bendix concern, because I experience it occasionally on my 2007 Seadoo GTI SE with 312 hours on it. Many probably are familiar with an automotive starter, that has both the starter motor and a Bendix solenoid/gear on the starter - when you turn the key on in your car, the solenoid energizes, overcoming the spring that pulls the Bendix back from the flywheel, and pushes the Bendix gear into your flywheel to turn the engine over with the starter motor providing the torque.
I am far from an expert here, but fundamentally I learned a while ago that the starter motor on a Seadoo is just the motor, and when you replace the starter, you are replacing just the motor. The Bendix is essentially a mechanical internal engine component, lubricated internally with engine oil, and has a spring that is overcome with the starter spinning and the Bendix is pushed into the flywheel to start the engine. I think the spring works in reverse from a car though, where the spring keeps the Bendix engaged on a Seadoo? Regardless, When you release the start button, the starter stops spinning, the Bendix pulls away from the flywheel, and the engine is now running.
My ski starts great cold, with the starter motor engaging the Bendix firmly and completely until the engine starts. When hot, and I am listening carefully or have the seat off, the Bendix will disengage and the engine stops turning over, and the starter is still spinning with a light spinning noise. I might have to try starting 2 or 3 times to get the Bendix engaged long enough to start the engine. I have made sure my battery is well charged and connections are all clean. I replaced the ground cable as a precaution and it didn’t change anything. I have contemplated changing the positive cable as a precaution, but haven’t - I don’t think it is a problem. The dealer told me the issue is that the Bendix spring is old and weak, and is affected by temperature, and that is why I sometimes get it disengaging after just a second or two of turning the engine over. The kicker: you have to either pull the engine or do some major work to replace the Bendix and I am not up for it, on a ski works well enough. My dealer quoted me minimum $1200 in labor and no guarantee the Bendix is 100% the issue because they can’t duplicate the concern without riding around an hour or two and letting the ski sit for a while and hot soak like I do when enjoying a day on the river. The ski is in great shape, and maybe I will have to do it someday…
So after you make sure you have a good battery, connections clean and good, and cables are good - listen to see if you hear your starter spinning and not turning the engine over - that could indicate a Bendix spring concern when hot. Hope most of this is helpful and directionally correct for other novices like me.