Exhaust temp

[Scarlett]

My engine is running at the correct temperature, about 175 at 1200 RPM, however the exhaust temp at different places on one engine is a lot higher. The exhaust line in the aft cabin is about 165 and only about 130 on the other engine. At the injection elbow 90 on one and 130 on the other. Seems as simple as to low seawater flow, but the engine itself is not running to hot. Suggestions please, John

 

[racclarkson@gmail.com]

John, way too hot. If the motor runs cool you’re pumping enough water. If the pipe is hot, I’d go to the shower head. To start, can you compare the outflow at the transom? Reving up should show up better. Can you also verify the hot side continues to drain water after the cool side has stopped? That should be a good indicator of a partially blocked shower head.

 

[oscarvan]

John, way too hot. If the motor runs cool you’re pumping enough water. If the pipe is hot, I’d go to the shower head. To start, can you compare the outflow at the transom? Reving up should show up better. Can you also verify the hot side continues to drain water after the cool side has stopped? That should be a good indicator of a partially blocked shower head.

This is something I need to check too.....

But honest question.... If the shower head is (partially) clogged, how can it pump enough water for the engine to stay cool?

 

[Scarlett]

Robert, thanks for that, it was the first thing that I thought of. Can the rubber hose connecting the exhaust elbow to the fiberglass exhaust piping be pulled down enough to see up inside to the shower head or shoul it be removed from the turbo?

 

[racclarkson@gmail.com]

Robert, thanks for that, it was the first thing that I thought of. Can the rubber hose connecting the exhaust elbow to the fiberglass exhaust piping be pulled down enough to see up inside to the shower head or shoul it be removed from the turbo?

John, can on mine. Once, I used some very heavy mil plastic and made a damn under my shower head. Then I was able to fill the shower head with phosphoric acid/water for cleaning. Now mine wasn’t clogged, so I can’t say it’d help yours. But it might be worth a try before resorting to pulling. Oscar, there is tons of volume in the raw water system. It could easily cool the motor with reduced exit flow given the sea water temp where John’s located plus I think he runs mostly hull speed.