I have had my Yamaha vmax 225 for about a year and was wondering when I should change the fluid?

YES !

You should of already changed it, especially if it was brand new.I do mine once a season.

Change the water pump and lower unit oil once a year or you will be sorry.

If you haven't replaced it yet put some Amsoil Synthetic. Also get some of the Syntheic oil for you mix. You can stop using the Yama Ring Free as well.

Ken is right about both

Pull the bottom Plug and check fluid. Might have shavings around and in that case would change. Also if its appears milky- might have a seal or impellar bad. Its very easy to change or get someone to do it.I didnt change mine for awhile and now do it on a regular Basis. Not hard to do either

I change my once a year. Its a bad sound when the alarm goes off 10 miles from ramp.Fluid and impellar.

thanks guys. I am a coach not a mechanic. how hard is it to replace the water pump?

I have always paid someone to do it. But I have been told its not hard.The pump or impellar is just a rubber gear looking thing that slides over shaft.Maybe someone on here can explain the procedure.

Its not hard if you know what you are doing and are handy with tools and have the right tools, if not, I would have a repair shop do it.