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Concerned about safety and looking for suggestions:
My A4 is in a 1971 C&C 35 that I've owned for less than a year. Surveyor thought engine was rebuilt relatively recently. Last Oct. I bought it with a small amount of steam exiting the exhaust (didn't recognize it for what it was at the time), motored it immediately most of the way for about 12 hours over the course to two days to its new marina, and had run it under load briefly and without incident once this year before Memorial Day, when during its first substantial cruise the steam increased, water flow out the exhaust stopped, the engine overheated, and the old copper stack muffler started dropping water out the bottom. I had to let it cool down completely and limped back to port in two 5 minute hops (water flowed well at first during each hop but then stopped and we shut it down as the temp increased).
Upon inspection afterwords, found several problems - a piece of crud blocking the water outlet from the manifold to the muffler, the muffler severely corroded and leaking, and the thermostat housing so badly corroded the thermostat valve could not function correctly (the thermostat itself works perfectly). Replaced: (a) the muffler with the Moyer S/S water lift; (b) all the water hoses and fittings, (c) the thermostat housing; (d) the hot section of the exhaust using galvanized pipe and wrapped it in the tape sold by Moyer; and (e) installed new exhaust hose from the muffler to the discharge.
Took the boat out for a test run this past weekend and the water temperature stayed perfect - in the 140s - under all conditions and throughout the trip. Water flow out the exhaust was also great. Engine sounds a little rougher than I remember but otherwise okay. However, after 10 minutes of motoring, there was this unusual smell and some light-colored smoke that I couldn't identify coming from the engine compartment. I shut the motor and sailed for a few hours but when I started it back up to get back to the dock, the smell returned (but not so much smoke).
Looking for suggestions as to a source of the smell/smoke. I don't think its exhaust fumes - smells earthier/woodier and it didn't trip the CO alarm. It was closer to a natural burning smell but not plastic or rubber. I checked the engine compartment and nothing was too hot or touching the hot section of the exhaust. The fiberglass walls of the engine compartment were cool to the touch. The only other changes have been the spark plugs, which I upgraded to the hotter copper ones suggested on another part of this forum, and an oil change.
I'm stumped.
Wild guesses: The new brown cloth insulating tape wrapping the galvanized pipe? Odd if the engine is at normal temp and the tape is designed for this application. The new wood shelf on which the muffler sits? But the muffler is pretty cool to the touch. Boiled Chesapeake Bay crud getting cooked inside the engine? But how would the smell escape into the engine compartment?
Any advice or suggestions would be very welcome as the smoke/smell is disconcerting and I had been hoping to bring the family and friends aboard soon.
Thanks,
Mike
My A4 is in a 1971 C&C 35 that I've owned for less than a year. Surveyor thought engine was rebuilt relatively recently. Last Oct. I bought it with a small amount of steam exiting the exhaust (didn't recognize it for what it was at the time), motored it immediately most of the way for about 12 hours over the course to two days to its new marina, and had run it under load briefly and without incident once this year before Memorial Day, when during its first substantial cruise the steam increased, water flow out the exhaust stopped, the engine overheated, and the old copper stack muffler started dropping water out the bottom. I had to let it cool down completely and limped back to port in two 5 minute hops (water flowed well at first during each hop but then stopped and we shut it down as the temp increased).
Upon inspection afterwords, found several problems - a piece of crud blocking the water outlet from the manifold to the muffler, the muffler severely corroded and leaking, and the thermostat housing so badly corroded the thermostat valve could not function correctly (the thermostat itself works perfectly). Replaced: (a) the muffler with the Moyer S/S water lift; (b) all the water hoses and fittings, (c) the thermostat housing; (d) the hot section of the exhaust using galvanized pipe and wrapped it in the tape sold by Moyer; and (e) installed new exhaust hose from the muffler to the discharge.
Took the boat out for a test run this past weekend and the water temperature stayed perfect - in the 140s - under all conditions and throughout the trip. Water flow out the exhaust was also great. Engine sounds a little rougher than I remember but otherwise okay. However, after 10 minutes of motoring, there was this unusual smell and some light-colored smoke that I couldn't identify coming from the engine compartment. I shut the motor and sailed for a few hours but when I started it back up to get back to the dock, the smell returned (but not so much smoke).
Looking for suggestions as to a source of the smell/smoke. I don't think its exhaust fumes - smells earthier/woodier and it didn't trip the CO alarm. It was closer to a natural burning smell but not plastic or rubber. I checked the engine compartment and nothing was too hot or touching the hot section of the exhaust. The fiberglass walls of the engine compartment were cool to the touch. The only other changes have been the spark plugs, which I upgraded to the hotter copper ones suggested on another part of this forum, and an oil change.
I'm stumped.
Wild guesses: The new brown cloth insulating tape wrapping the galvanized pipe? Odd if the engine is at normal temp and the tape is designed for this application. The new wood shelf on which the muffler sits? But the muffler is pretty cool to the touch. Boiled Chesapeake Bay crud getting cooked inside the engine? But how would the smell escape into the engine compartment?
Any advice or suggestions would be very welcome as the smoke/smell is disconcerting and I had been hoping to bring the family and friends aboard soon.
Thanks,
Mike
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