One hard freeze is all it takes. Water left in an engine expands as it freezes and can crack a block, a manifold or a heat exchanger overnight. If your Rogue Jet runs an Indmar Raptor 440 or Raptor 575, winterizing is straightforward, and this guide walks through exactly how we do it here in White City, Oregon.
Quick answer: how do you winterize an Indmar Raptor 440 or 575?
Run the engine to operating temperature with fuel stabilizer in the tank, change the oil and filter while it is warm, then drain every raw-water component: the heat exchanger, sea strainer and raw-water pump hoses. Confirm the closed-cooling coolant is rated for your coldest temperatures, disconnect the battery, and store the boat covered with the engine compartment ventilated.
Why the Raptor 440 and 575 are easier to winterize
Both engines are built on Ford’s 6.2L SOHC V8. The Raptor 575 adds a ROUSH supercharger and is rated at 510 hp and 580 lb-ft of torque. The Raptor 440 is the naturally aspirated version.
The key to both is closed cooling. Like the radiator system in your truck, the engine block is filled with antifreeze coolant that never touches lake or river water. Lake or river water only passes through a separate raw-water circuit that cools the coolant through a heat exchanger. Indmar designed the Raptor series with self-draining manifolds and fewer parts that need draining.
That means winterizing is mostly about one thing: getting every drop of raw water out of the raw-water side, and making sure the coolant on the engine side is good to your coldest local temperature.
What you’ll need
- Marine fuel stabilizer
- Indmar-approved engine oil and a new oil filter
- Antifreeze tester (hydrometer or refractometer)
- Indmar or marine-grade antifreeze, if the coolant needs topping off
- Fogging oil (see your Indmar owner’s manual)
- Waterproof marine grease
- Drain pan, rags and basic hand tools
- Battery maintainer
- Boat cover
Step-by-step: winterizing your Indmar Raptor 440 or 575
- Fill and stabilize the fuel. Add marine fuel stabilizer to the tank, then top it off. A nearly full tank leaves less room for condensation over the winter.
- Run the engine to operating temperature. Run the boat in the water. Never run the main engine out of the water. Let it run at least 15 minutes so stabilized fuel reaches the injectors and fuel lines.
- Change the oil and filter while warm. Warm oil drains more completely and takes the season’s contaminants with it. Old oil left over winter can hold moisture and acids.
- Drain the raw-water side. This is the most important step. Shut the engine off and drain the heat exchanger, the sea strainer and the raw-water pump hoses. Remove the drain plugs and let everything empty completely. Watch our video below: it shows every drain point on our boats so you don’t miss one.
- Check the closed-cooling coolant. Test the antifreeze with a tester. It needs to be rated well below the coldest temperature your boat will see. Top off or replace with Indmar-approved coolant if needed. Do not drain the coolant side.
- Drain the jet pump and clear trapped water. Make sure the pump and intake area are empty and free of debris.
- Grease and lubricate. Grease the pump.
- Take care of the battery. Disconnect it, or put it on a marine battery maintainer for the winter.
- Clean, dry and ventilate. Pump and dry the bilge. Prop the engine cover open about 2 inches so the compartment can breathe, then cover the boat.
Video: draining the water from an Indmar Raptor engine
In this video, we walk through the draining procedure step by step on a Rogue Jet inboard. Watch it before you start, and keep it open on your phone while you work.
Video: changing the oil and fuel filter on an Indmar Raptor engine
In this video, we walk through the oil change and fuel filter change step by step on a Rogue Jet inboard. Watch it before you start, and keep it open on your phone while you work.
Winter storage tips for your aluminum boat
- Store it covered and dry. A fitted cover or indoor storage keeps rain and snow out of the bilge, where it can freeze.
- Keep the bow slightly high. Any water that does get in will run to the drain plug.
- Pull the drain plug. Leave it out while stored, and put it somewhere you’ll see it in spring, like on the steering wheel.
- Keep critters out. Plug exhaust outlets and intakes loosely, and remove food from storage compartments.
- Check on it monthly. Look at the cover, the battery charge and the bilge.
When to call Rogue Jet
Indmar itself recommends having a dealer winterize your engine, and damage from improper winterization is not covered by the engine warranty. If you are short on time, unsure about a step, or want peace of mind, give us a call. We build these boats, and our crew knows every drain point on them.
Have a question? Contact Rogue Jet Boatworks at 541-826-5400
Frequently asked questions
Do I need to drain the coolant on a closed-cooled Indmar Raptor? No. The closed-cooling side holds antifreeze coolant and should stay full. Test it to confirm it is rated below your coldest expected temperature, and drain only the raw-water side.
What happens if I don’t winterize my boat engine? Water left in the raw-water side can freeze, expand and crack the heat exchanger, pump or hoses. Repairs are expensive, and freeze damage is not covered by Indmar’s engine warranty.
When should I winterize my boat in Oregon? Before the first hard freeze, usually mid-October to early November in the Rogue Valley. Higher-elevation and northern boaters should plan earlier.
Is winterizing the Raptor 575 different from the Raptor 440? The process is nearly identical because both are built on the same Ford 6.2L closed-cooled platform. The 575’s supercharger does not add raw-water drain points, but always follow the owner’s manual for your specific engine.
How long does it take to winterize an Indmar inboard? Most owners finish in one to two hours, including the oil change. Having all supplies on hand before you start saves time.