Flatswing
Guru
- Joined
- Sep 21, 2016
- Messages
- 580
- Location
- United States
- Vessel Name
- River Girl
- Vessel Make
- 2004 DeFever 49 RPH
1000hrs on this genset which usually runs well. (Heat exchanger was replaced 2 yrs ago by PO. Raw water circuit flushed w Barnacle Buster & new impeller prior to cruise).
Cruise-Day 2: slow to fire-cranking ~20 secs before all cylinders firing then runs fine with or without load, no smoke. Cold starting problem continues, so starting with thru-hull closed initially each time. Warm restart-no problems.
Cruise Week 2: got to marina, replaced 2 glow plugs + primary & secondary fuel filters (No air leak found, fuel tank level is well above the lift pump).
Cruise Week 5: white smoke in exhaust no engine overheat- 2 mos old impeller replaced (the 2 sheared vanes retrieved from pump outflow elbow).
Week 10: post cruise oil change usual color & smell but Blackstone analysis (attached) shows high sodium & potassium at 24:1 ratio so most likely seawater with secondary wear, perhaps some rust from sitting for several mos. pre-cruise?
I am thinking the most likely causes for the sea water intrusion would be either through the raw water pump seal or (more likely?) back up from exhaust elbow. Going to the boat tomorrow to check pump and exhaust elbow, probably replace both, then run under load for 10-20 hrs and retest.
Any suggestions or further advice greatly appreciated?
Cruise-Day 2: slow to fire-cranking ~20 secs before all cylinders firing then runs fine with or without load, no smoke. Cold starting problem continues, so starting with thru-hull closed initially each time. Warm restart-no problems.
Cruise Week 2: got to marina, replaced 2 glow plugs + primary & secondary fuel filters (No air leak found, fuel tank level is well above the lift pump).
Cruise Week 5: white smoke in exhaust no engine overheat- 2 mos old impeller replaced (the 2 sheared vanes retrieved from pump outflow elbow).
Week 10: post cruise oil change usual color & smell but Blackstone analysis (attached) shows high sodium & potassium at 24:1 ratio so most likely seawater with secondary wear, perhaps some rust from sitting for several mos. pre-cruise?
I am thinking the most likely causes for the sea water intrusion would be either through the raw water pump seal or (more likely?) back up from exhaust elbow. Going to the boat tomorrow to check pump and exhaust elbow, probably replace both, then run under load for 10-20 hrs and retest.
Any suggestions or further advice greatly appreciated?
