I've looked through the past threads and can't seem to find the answer to my question. I have a new (to me) inboard/outboard 4.3l mercruiser that I keep on a trailer, that I want to use for the winter fishery. What do I need to do to keep the motor from freezing while on the trailer? I know what to do if it were to live on the trailer until spring, but I want to use to use it through the winter. I hope I don't need to winterize after each use! I was thinking of getting an engine compartment heater, as the boat is under cover. Looking to you old pro's for any info.
Winterizing IB/OB that I want to use through the winter
- Thread starter Blueback
- Start date
SpringVelocity
Crew Member
There isn't much to do if your running in winter.
Don't winterize it. All I do is flush and drain manifold, and then drain the water of heat exchanger (fresh water cooled system). That's it. I don't put a heater in mine, and its kept under a boat shelter.
Only additional thing is I just open the doghouse a bit so air circulates, and open the hatches where batteries are.
Don't winterize it. All I do is flush and drain manifold, and then drain the water of heat exchanger (fresh water cooled system). That's it. I don't put a heater in mine, and its kept under a boat shelter.
Only additional thing is I just open the doghouse a bit so air circulates, and open the hatches where batteries are.
Last edited:
RogersonCrusoe
Well-Known Member
In addition, if it's going to get very cold overnight, I've hung a troublelight inside the motor cover to keep the interior warm. I put it on a timer so it turns on for a couple hours.
Fixit
Well-Known Member
depends on how cold it gets and for how long. -1or -2 and you could just put a heater in the bilge under the engine. (not something with a fan, use and airdry convection heater or 100W lightbulb etc
if its going to be below freezing for a sustained time like more than a few days, or daytime temps don't go above zero, then I usually drain everything or run coolant through the freshwater side of things. my boat is full coolant system so I just have to worry about the heat exchange, hoses, pump etc.
look into something like a hot start coolant heater. I think it may be just the ticket for you
if its going to be below freezing for a sustained time like more than a few days, or daytime temps don't go above zero, then I usually drain everything or run coolant through the freshwater side of things. my boat is full coolant system so I just have to worry about the heat exchange, hoses, pump etc.
look into something like a hot start coolant heater. I think it may be just the ticket for you
Foxsea
Well-Known Member
If you boat in saltwater and your FWC boat is stored on the coast, not a big issue. Don't flush it. Saltwater only freezes below 2 degrees C. so rarely will it freeze here. Also the doghouse insulates the engine somewhat. As Rogerson and Fixit suggest, if it's forecast to be colder than - 3 C. for a few days (rare), use the incandescent trouble light or a small heater. I have done this for years without consequence.
SpringVelocity
Crew Member
Never had an issue with cold weather without running heaters, but you can put a heater of you want to. Must important thing is drain your manifold/ex changer if you ave fresh water system.
I also have done this for years. I am on island and we do have cold snaps but most of time its above freezing.
Always flush your inboard when you finish with it then drain it. You don't want to leave saltwater in your manifold for extended period of time.
I also have done this for years. I am on island and we do have cold snaps but most of time its above freezing.
Always flush your inboard when you finish with it then drain it. You don't want to leave saltwater in your manifold for extended period of time.
Awesome replies guys; much appreciated. I want to get on this before it becomes an emergency, as the climate is becoming more erratic. My boat has an open system that circulates ambient water salt/fresh water, and I almost always launch at MacDonald beach so the engine gets a chance to circulate Fraser River water before it goes on the trailer. I live up on Capitol Hill in Burnaby, so it is always a couple of degrees colder than what is listed for Vancouver (reported from the airport). Some years we get a lot of snow up here as well and sometimes sustained sub zero for a week or two. I will look for drain plugs for the manifolds and make sure all the water is out and the leg is down and drained. I think I'll get a heater for the bilge, as those old light bulbs are hard to find these days. I also need to think about the toilette, freshwater system in the galley, washdown system and the heater core in the V-berth.
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