Hello all, getting a bit frustrated after a two minute brain fart... Had muffs on, water running, dead battery... got out to hook up jump and turned off water, forgot to turn it back on, ran at 1800 until i saw smoke (maybe 2 mins), glanced at water guage and was maybe around 180 at that moment (normal idle is 130-140), jumped out and turned on municipal water and allowed it to return to normal temp then shut down, engine running and sounding normal. Black chunks on the driveway coming from the exhaust.
What I found... removed lower unit, impeller was still in great shape with no damage (maybe since I had the water on at one point?) but I replaced it, the 3 gaskets, 2 rubber seals, keyway, and greased splines anyhow since I had bought one expecting it to have failed and it hadn't been replaced since I got the boat 2 seasons ago. Did not replace housing since it appeared in great shape with no scoring. Plastic guide cap for copper water line was warped, but i heated it up and straightened it back ou well enough. Water pocket divider appeared complete. Bellows and shift cable boots in good shape. Shutters (brand new 2 seasons ago) were totally cooked and flaps have fallen down the Y pipe but not the crossbars. Replaced flaps but did not fish out the metal "heels" yet.
Problem... put everything back together and fired it up with muffs on (and water running - haha) and drive down, the engine sounds good, water is flowing out the side ports at top of unit, though not convinced water is coming out the prop though, hard to tell, but with good exhaust gas flow... Also, when I fill up a 15 gallon bucket up past the cavatation plate with engine running at perhaps 1200 RPM and muffs on everything seems good with big exhaust bubbles out prop. BUT! When I remove the muffs and turn off the water, about 10-15 seconds later water flow diminishes greatly and exhaust actually stops bubbling out the prop, as if water flow has ceased and the exhaust is filling up with water causing exhaust back pressure so I return the muffs and turn on the water and water exits at the top of unit and exhaust resumes bubbling. Is that normal for the exhaust to appear to stop entirely and the water flow to nearly stop at low RPM? I'm leary of letting it continue that way so I don't cook it again. But to me this simulates standing still in the lake with engine running and doesn't seem like proper function?
Is that normal and what else should I look for? Would the "heels" be causing a blockage that only seems to appear when municipal water pressure is removed? I know I need to get the heels out of the bellows or the Y pipe, but was looking for proper function before tracking those down.
What I found... removed lower unit, impeller was still in great shape with no damage (maybe since I had the water on at one point?) but I replaced it, the 3 gaskets, 2 rubber seals, keyway, and greased splines anyhow since I had bought one expecting it to have failed and it hadn't been replaced since I got the boat 2 seasons ago. Did not replace housing since it appeared in great shape with no scoring. Plastic guide cap for copper water line was warped, but i heated it up and straightened it back ou well enough. Water pocket divider appeared complete. Bellows and shift cable boots in good shape. Shutters (brand new 2 seasons ago) were totally cooked and flaps have fallen down the Y pipe but not the crossbars. Replaced flaps but did not fish out the metal "heels" yet.
Problem... put everything back together and fired it up with muffs on (and water running - haha) and drive down, the engine sounds good, water is flowing out the side ports at top of unit, though not convinced water is coming out the prop though, hard to tell, but with good exhaust gas flow... Also, when I fill up a 15 gallon bucket up past the cavatation plate with engine running at perhaps 1200 RPM and muffs on everything seems good with big exhaust bubbles out prop. BUT! When I remove the muffs and turn off the water, about 10-15 seconds later water flow diminishes greatly and exhaust actually stops bubbling out the prop, as if water flow has ceased and the exhaust is filling up with water causing exhaust back pressure so I return the muffs and turn on the water and water exits at the top of unit and exhaust resumes bubbling. Is that normal for the exhaust to appear to stop entirely and the water flow to nearly stop at low RPM? I'm leary of letting it continue that way so I don't cook it again. But to me this simulates standing still in the lake with engine running and doesn't seem like proper function?
Is that normal and what else should I look for? Would the "heels" be causing a blockage that only seems to appear when municipal water pressure is removed? I know I need to get the heels out of the bellows or the Y pipe, but was looking for proper function before tracking those down.
