Flushing a freshwater cooling system on a bayliner 245?

[Rain City]

I'm having temp issues and was told to flush my heat exchanger. Brand new leg on it now but it's always run hot. Any thoughts?

 

[Filletandrelease]

Most heat exchangers have caps on the ends held by a single bolt. Pretty simple to pull the ends off and look thru it. Will be obvious if it is plugged in any way.

 

[Goathorns]

you can get them boiled out at a rad shop.