I have a 35 Fountain with 496 ho's and after replacing the water pump with a new one one the motor is still running 10 deg to high , I pulled the heater exchanger and cleaned it but was just wondering how do I reverse flush the system so I could try to get any trash out of the oil cooler. Thanks for any help. Blake

Take the hose off the raw water pump. Then take the port hose off the close cool heat exchanger (log on front of your engine) put a garden hose in it full bore!

Few other things you might check:
1 - You sure its not stuck in the riser? Flush it too.
2 - When the close cool log was off, take the ends off and run a coat hanger thru all the holes. I clean mine with muratic but some say thats bad...
3 - Sure its not blocked at the low water pickup? Last season I hit an old piece of rotted wood and it plugged all my low water pickup holes.

Did you remove the old impeller in one piece, or is/was some (piece/parts) missing?

Also, how old is your antifreeze? It only get's about 6 or 7 seasons on it before it starts to silt up and lose flow. If it's pink, its good to go. If it's starting to get grey/metallic in color, it's time to change.