T
Tom Tarlton
Guest
"Hello all. My boat has a pai
"Hello all. My boat has a pair of fuel injected MIE 8.1 Horizons. En-route to marina for refueling, I noted both engines could not get over 3000 rpm. Eventually traced problem to marine growth on props, with rest of hull fine. After cleaning, took her out and both engines ran fine again, reaching 4300 rpm at wot, and boat speed up to 32 knots. (I normally cruise at 2700 rpm, rarely taking it up to 3600, and only to wot probably 2 or 3 times, but only briefly.)
During docking, starboard transmission (ZF/Hurth 630A) began making exaggerated clacking sounds in forward gear, nothing unusual in reverse. Shut her down. About 2 hours later, decided to check out the sounds, so I attempted to start the engine, but it would not turn over. I could hear the starter motor engage but that was it (8D battery 1 week old). After the work week, tried starting engine again, and it turned over on second attempt, starting up. Checking cooling water flow at stern (closed system), I noticed it was a bit milky, and a sheen formed on canal surface. Checking the exhaust vent on boat's side, I noted the smell of gas vapors in the exhaust. Ran engine at idle for about 5 minutes and odor and milky cooling water did not disappear. It did not appear to be running very rough, sounding almost normal.
I thought one cylinder might not be firing, so I pulled the spark plugs on the easy side and they looked good. Did not pull the four on the outboard side. Decided to run a spark coil test before doing anything else. All 8 coils are working fine with good spark noted. Have yet to pull the plugs on the outboard side.
Any ideas about this before I proceed? I have put a code reader to it and there have never been any alarms registered on this engine for overheat or low water flow, etc (all system sensors are ok also). It is the same engine which has another post for the hot cast iron manifold."
"Hello all. My boat has a pair of fuel injected MIE 8.1 Horizons. En-route to marina for refueling, I noted both engines could not get over 3000 rpm. Eventually traced problem to marine growth on props, with rest of hull fine. After cleaning, took her out and both engines ran fine again, reaching 4300 rpm at wot, and boat speed up to 32 knots. (I normally cruise at 2700 rpm, rarely taking it up to 3600, and only to wot probably 2 or 3 times, but only briefly.)
During docking, starboard transmission (ZF/Hurth 630A) began making exaggerated clacking sounds in forward gear, nothing unusual in reverse. Shut her down. About 2 hours later, decided to check out the sounds, so I attempted to start the engine, but it would not turn over. I could hear the starter motor engage but that was it (8D battery 1 week old). After the work week, tried starting engine again, and it turned over on second attempt, starting up. Checking cooling water flow at stern (closed system), I noticed it was a bit milky, and a sheen formed on canal surface. Checking the exhaust vent on boat's side, I noted the smell of gas vapors in the exhaust. Ran engine at idle for about 5 minutes and odor and milky cooling water did not disappear. It did not appear to be running very rough, sounding almost normal.
I thought one cylinder might not be firing, so I pulled the spark plugs on the easy side and they looked good. Did not pull the four on the outboard side. Decided to run a spark coil test before doing anything else. All 8 coils are working fine with good spark noted. Have yet to pull the plugs on the outboard side.
Any ideas about this before I proceed? I have put a code reader to it and there have never been any alarms registered on this engine for overheat or low water flow, etc (all system sensors are ok also). It is the same engine which has another post for the hot cast iron manifold."