Exhaust cooling Scarab 165

[Divouneh]

You are flushing the exhaust circuit after each use in salt water with pressurized raw water. When running the boat, how does the water reach the exhaust system : Do we have a pump ( as the engine cooling) or any circulation done with the water use to move the boat ?
Do we have a drawing from this circuit?

 

[Luc Lafreniere]

The intake is inside the pump. At the top of the pump, right behind the impeller, there's a tiny grill if you look inside carefully. The pump pressurizes the water and it forces it through that intake grill, then through the hull via a "reducer" which is washer that is colour coded based on how much water it allows through. Then it flows into the exhaust system and makes its way out via the giant hole on the port side of your jet nozzle.

This is also why you can't tow a BRP engine too fast. If you do, the impeller starts turning because of the water flowing through it which creates pressure and forces water into the exhaust system. If the engine isn't running, there's no back pressure preventing it from going ALL the way up into the engine itself. Hence tow slow or clamp the intake hose(s).

There are diagrams and I think a video for Sea-Doo/BRP, but I'm at the cottage with little to no reception so I can't search for it right now.

 

[Divouneh]

Thanks Luc