I like to change the coolant on a 2 year cycle, and I believe this is also a Seadoo recommendation. I agree with the others here, the coolant will more than likely last for much longer than 2 years; but how do you really know. Sure, there are testers out there but I just don't trust them.
I worry about the coolant's ability for corrosion protection. When new it has corrosion inhibitors and lubricants to keep the system clean and sealed. When the fluid goes bad, things start to happen fast and you get internal corrosion, seals start leaking, etc. The corrosion starts in parts of the engine that you really can't see and you might never know the degradation is there. I have seen old car engines and radiators that have not been maintained and it's not pretty. The 4-tec cooling system is aluminum and some of the parts, like the heat exchanger, have very small tight passages that could fail with the least amount of internal damage. This can be costly to fix.
I prefer to error on the side of safety which is why I practice preventative maintenance, maybe a bit to the extreme. Why not? Changing the coolant is one of the easiest and inexpensive maintenance items to do on these machines. I am a big fan of the Seadoo closed loop cooling system and it puzzles me why more marine manufacturers do not use something similar, especially for salt water use. I see it as a definite benefit and not a drawback by any means. Let us know if you need any tips doing this for the first time yourself.
It is so easy to do and inexpensive.
