Chevy 350 with thru hull exhaust. Somehow managed to burn up the rubber hose, internal flapper, and external rubber flapper on one side of the motor.

http://www.offshoreonly.com/gallery/...19639&cat=3071

Any idea(s) how this could happen? I'm thinking I must have lost water, but when I smelled the burning rubber I stopped the boat and opened the hatch while idling and I could keep my hands on the exhaust risers. Temp gage never went up either. Started the boat up the next day and water was gushing out at idle. All the rubber from the internal flapper turned to a complete molten state and is now spattered on my transom.

Poppet/check valves in the thermostat tee? Can I take them out?

Thanks!

Do you have silent choice? - If you do make sure both dampers are opening. If one doesn't open that side will have higher back pressure and may stop water flow to that side.

No silent choice. Riser connects to a 3" rubber hose about 3 ft long that has/had an internal flapper and goes straight back to transom. Stock thru hull exhaust on a 86 Formula F206.

I'd pull all the cooling lines you can and back flush with air and water. You may have ingested some debris, OR perhaps debris covered the water intake for a period of time then self extracted. Plastic bags floating in or just under the surface can be an issue at times.

I have had that issue in the past, so it does happen! Expensive lesson I learned from other peoples trash!

The lake has had a lot of clumpy weeds/scum piles near syrface. Glad I sat down and got behind the windshield and got a whiff of the burning rubber. Otherwise I'd kept on running it and probably started a fire.

Or another thing is a loose belt on the seawater pump. Could have some grip at idle but slips at higher rpms and giving you water through the system.