Proper Flushing Of Jet Boat

[Jburke]

Im looking for some insight on how to properly flush the entire cooling system on a 79 Thahiti w/Panther Jet. It has 454 Big Block, but the last time I took it out the temp raced to near red-line. Does anybody have any tips?

[Riverjet502]

Just disconnect the cooling line coming off the jet pump (probably easier at the "Y" pipe) and attach a fitting to this line that will allow you to connect a garden hose to it. Very simple. On mine I just pull the cooling hose off the pump and slide a small piece of garden hose over the bib on the through hull fitting and flush away...

[jburke1]

I've Flushed It As Instructed And Replaced The Thermostat With An "oe" One. It Is Still Getting Hot! With The Garden Hose Attached, Water Flows Evenly From Both Exhuast Ends. I Dont See Any Evidence Of Water In The Oil, So I'm Not Sure What Is Causing This Issue. Any Ideas?

[Riverjet502]

OK it sounds like your t-stat is not opening. They don't like silt and sand very well. If you are using a automotive thermostat take it out and do not use it. I am assuming that you are running "wet" exhaust. If you desire to run a thermostat you need to run a thermostat byepass kit. Rex Marine or CP Performance sells these. I don't run a T-stat in my jet. My cooling comes off my pump goes through a thru-hull fitting then into a gate valve. From the gate valve the cooling is plumbed into a V-pipe which sends water to my Gill exhaust manifolds on each side of the engine. After the water is pre-heated from the exhaust manifolds it goes into the front of the block. After circulating in the block and heads it comes out the t-stat housing (which has no t-stat) where it dumps into the risers to cool the exhaust since I have an enclosed engine compartment. The reason for the gate valve is so that I can control the amount of water entering the cooling system. This also acts like a reducing valve so that I don't over pressureize the cooling system and milk shake my oil. Hope this helps alittle.

[Frosty]

Exellent post --

[jburke1]

Great help!!!! I really appreciate your recommendations. By the way, you solved my overheating issue. YES!

[Riverjet502]

Glad to help out.....