I have 2005 yamaha 300 hpdi. about 180 hours... My dad has winterized it that last couple of years. Should I take it to a yamaha guy and have a new impeller or anything else done or "if it aint broke....." any advice would be greatly appreciated..
Well past time to change the water pump assembly, not just the impeller - the plates also wear and the housing can be deformed over time. Yamaha sells the whole kit for not much more than the impeller itself.
East DIY project if you are so inclined, otherwise go see the dealer.
NOT a place to scrimp on the $$.
I was told by yamaha to change my water pump on my 300 once a year, if you run any amount of saltwater at all, they have a week pump on them, they are a low volume pump and if the impeller wears a little or loses any elastisaty it cuts the volume down and it will over heat at low idle this is a fact I had this happen to me. For 70.00 dollars I will change mine once a year, very easy job but also replace the anti knock ring thats on the shaft just above the water pump housing, thats a little tricky to get off but take your time and use equal force to pry off.
Also another tip to save you some head aches is change the inline filter on the oil tank once a season its only 15.00 dollars