sportpilot
Cadet
- Joined
- Aug 7, 2008
- Messages
- 16
Long story short, I have a 1994 Evinrude V4 Looper - E120TLERC with an overheating problem...
I bought the boat used and decided that the best bet would be to go ahead and pull the lower unit and replace the water pump and I also pulled the thermostats and heads to check for excessive carbon buildup and/or steaming.
Thermostats were ok and tested alright to start opening at about 145 F...the heads looked great with minimal carbon buildup on heads and pistons...the water pump impeller was intact with no apparent signs of damage...so I am a bit stumped at this point.
The aspirator (BPR Part #914902) has two ports coming in at an angle and the the larger port from the top. I understand the venturi effect from the side ports that sucks water from the top port which is connected to the siphon valve in the motor pan, but my question is which port should be connected to the water outlet from the port head? It was connected to the smaller top port which has an ID of ~ 0.10"...but this port is reduced as it nears the inside of the aspirator to just over 0.050". The larger port on the bottom is just over 0.20" ID...which port should be used?
What I was seeing when this engine was overheating was ~ 29-32 psi of water pressure at WOT @ 6100 RPM. The water flow from the tell tale was steady but not strong...I have a 13 7/8 X 19 Viper prop and was getting about 48 mph fully trimmed out...
Hope someone can help me out...
I bought the boat used and decided that the best bet would be to go ahead and pull the lower unit and replace the water pump and I also pulled the thermostats and heads to check for excessive carbon buildup and/or steaming.
Thermostats were ok and tested alright to start opening at about 145 F...the heads looked great with minimal carbon buildup on heads and pistons...the water pump impeller was intact with no apparent signs of damage...so I am a bit stumped at this point.
The aspirator (BPR Part #914902) has two ports coming in at an angle and the the larger port from the top. I understand the venturi effect from the side ports that sucks water from the top port which is connected to the siphon valve in the motor pan, but my question is which port should be connected to the water outlet from the port head? It was connected to the smaller top port which has an ID of ~ 0.10"...but this port is reduced as it nears the inside of the aspirator to just over 0.050". The larger port on the bottom is just over 0.20" ID...which port should be used?
What I was seeing when this engine was overheating was ~ 29-32 psi of water pressure at WOT @ 6100 RPM. The water flow from the tell tale was steady but not strong...I have a 13 7/8 X 19 Viper prop and was getting about 48 mph fully trimmed out...
Hope someone can help me out...