View Full Version : Pro Star 1989 Exhaust issue maybe?

07-29-2012, 07:32 PM

I was cleaning the back of the boat today and realized my exhaust flapper seemed loose, upon removal I found it to be melted on the right side. I realize it is exhaust and it gets hot but this seems too hot.
The left side looks to be what i believe to be normal.

Does this look normal, just old?
Any ideas on what would cause this?

Boat runs consistantly 170 - 180 degrees all day.

1989 Prostar 190 351

Thank you in advance for any and all imput.


10-07-2015, 02:54 PM
WOW that's way hot. I have an 87 pro star 190 it runs 160 at 4000 rpm, my exhaust tubes are cracked but they did not over heat they leaked real bad. Have you checked your impeller?

Shaun R
10-07-2015, 03:23 PM
It only takes one high temp spike to start breaking down the exhaust hose. Replace before your boat starts to take on water.

Miss Rita
10-07-2015, 04:32 PM
Two concerns: Your boat runs 170-180 all day? That's too hot, do you have the right thermostat?

If one flapper is melted and the other isn't, it suggests to me that not much water is getting into that side. Run the engine while on the trailer, see if any water is coming out that side.

I suspect you'll need a new exhaust hose on that side.