A beautifully prepped pontoon boat docked next to a concrete launch ramp.

Avalon Boat Spring Startup Checklist | Get Your Pontoon Ready for the Water Without Costly Mistakes

ByClara Beckett

The sun is finally warm, the days are getting longer, and your Avalon has been sitting under that tarp since October — but before you hook up the trailer and race to the ramp, there’s a weekend of work that separates a smooth season opener from an embarrassing tow back to the dock.

TL;DR: Spring startup isn’t just about washing off the dust and turning the key. It’s a systematic inspection that catches problems before they leave you stranded. This checklist covers everything: trailer prep (because you can’t launch what won’t roll), battery revival, engine de-winterization (with the critical “never start dry” rule), hull and pontoon inspection, fluid checks, safety gear, and the all-important first start procedure. Follow these steps in order, and you’ll avoid the ten dumbest mistakes boaters make every spring.

Key Takeaways:

  • Check the trailer first — flat tires, dead lights, and dry bearings end your day before you reach the water
  • Never start your outboard without a water source — even for a few seconds destroys the water pump impeller
  • Inspect your pontoons for dents and leaks — water inside adds hundreds of pounds and kills performance
  • Replace the water pump impeller every 200-300 hours — it’s the #1 cause of spring overheating
  • Test your battery under load — a voltmeter reading isn’t enough to know if it’s good
  • Don’t change spark plugs before the first start — that fogging oil from winter will foul new plugs instantly

Why Spring Startup Is Different from Summer Maintenance

Here’s the thing about your avalon pontoon boat — it’s been sitting for months. Maybe in a cold garage. Maybe under shrink wrap outside. Maybe just under a tarp in your driveway. During that time, things happen. Rubber dries out. Corrosion forms. Critters move in. Condensation builds up inside the engine.

Summer maintenance is about keeping a running boat running. Spring startup is about waking up a boat that’s been hibernating — and doing it without breaking anything in the process .

One new Avalon owner asked on a boating forum: “I did all the service for winter that was in the book and stored it inside. Is there anything special I should do to get it ready?” The answer: follow the manual like a bible .

Did you properly winterize your boat last fall? If yes, spring startup is straightforward. If no, expect some surprises.

Phase 1: Trailer Inspection (Before You Move the Boat)

You can’t launch what won’t roll. The trailer is the most neglected piece of boating equipment, and spring is when that neglect shows up .

Tires:
Check the sidewalls for cracks (dry rot) and the tread for wear. Inflate to the pressure listed on the tire sidewall — don’t guess. Don’t forget the spare .

Wheel Bearings:
Jack up each wheel and spin it. Listen for grinding. Feel for roughness. If you greased them just before winter storage, don’t grease them again — the grease hasn’t been used, so it’s still good. Over-greasing can push grease out the back of the hub and fling it onto your clean boat .

Lights:
As any trailer owner can attest, the question in spring isn’t whether a trailer light is broken — it’s how many aren’t working . Test all running lights, brake lights, and turn signals. Corroded bulb sockets are the usual culprit.

Brakes and Hubs:
Test the brakes on a short trip around the block. After stopping, place your hand NEAR each hub (not on it!) to check for excessive heat. Extreme heat means bad bearings .

Winch and Safety Chains:
Inspect the winch strap for fraying. Check that the bow eye is secure. Make sure safety chains are intact and not rusted through .

Does your trailer have a spare tire? Most owners forget until they get a flat on the highway. Check it now.

Phase 2: Remove Covers and Inspect

Take off the tarp, shrink wrap, or storage cover. This isn’t just about uncovering the boat — it’s your first chance to see what happened over winter .

Check for Critters:
Mice love stored boats. Look for nests, droppings, or chewed wires. Pay special attention to storage compartments and under the engine cowl.

Inspect the Canvas and Vinyl:
Check your seats, covers, bimini top, and any other vinyl or canvas items for dirt, mildew, cracks, or tears. Clean with appropriate cleaners for canvas or vinyl and repair any holes .

Check the Pontoons:
Look under your boat thoroughly for any dents, damage, or potential leaks. Any problems should be dealt with immediately . If you notice one pontoon sitting lower than the other when the boat is on level ground, there may be water inside .

Inspect the Deck:
Check for soft spots, loose screws, or damage to the Non-Slip Marine Flooring.

When was the last time you really looked under your boat? Get down on your knees and inspect every inch of those pontoons.

Phase 3: Battery Revival

Your battery sat all winter. It needs attention before it will reliably start your engine .

Visual Inspection:
Check for cracks, bulges, or leaks in the battery case. If you see any of these, replace the battery immediately.

Clean the Terminals:
Use a wire brush to clean both battery terminals and the cable ends. Remove any white or blue corrosion . After cleaning, apply a thin layer of dielectric grease to prevent future corrosion.

Check Fluid Levels (Flooded Lead-Acid Only):
If your battery has removable caps, check the electrolyte level. Top up with distilled water only — tap water kills batteries .

Charge and Test:
Put the battery on a charger. Once fully charged, test it under load. A simple voltmeter reading isn’t enough — a battery can show 12.6 volts but still fail when you turn the key. Many auto parts stores will load-test your battery for free .

Reinstall Properly:
When reinstalling, connect the red (positive) cable first, then the black (negative) cable. This order reduces the risk of sparks near the battery .

Is your battery more than three years old? Even if it tests okay, consider replacing it. Spring is when old batteries die.

Phase 4: Engine De-Winterization (The Critical Part)

This is where most costly mistakes happen. Take your time. Follow the order.

Before You Start Anything

Remove the engine cowl. Visually inspect all wiring, hoses, and belts for cracks, loose connections, or rodent damage . Look for any signs of fuel or oil leaks.

Check the Propeller:
Inspect the propeller for any dents, damage, or fishing line wrapped around the hub. A bent prop vibrates and kills performance. Make sure the cotter pin is secure .

Check the Water Pump Impeller:
The water pump impeller is a rubber component that needs replacement about every 200-300 hours . If you’re not sure when it was last changed, do it now. A failed impeller is the #1 cause of spring overheating.

Fluid Checks:

  • Engine oil: Check the level and condition. If it looks milky, you have water contamination .
  • Lower unit gear lube: Check the level. The oil should be clear or light amber. If it’s milky, water has entered the gearcase .

Inspect Belts and Hoses:
Press your hand down on the belts. If they have a lot of give, replace them. Also look for soot near the pulleys — that’s a sign of a failing belt. Check all rubber hoses for cracks, soft spots, or swelling .

Are your spark plugs new? Don’t install them yet — wait until after the first run to avoid fouling them with fogging oil residue .

Phase 5: The First Start (Don’t Screw This Up)

This is the moment of truth. Do it wrong, and you’ll be buying a new water pump before the boat ever sees the lake .

Critical Rule: Never Start Without Water

Your outboard’s water pump is lubricated and cooled by the water it pumps. Running it dry, even for a few seconds, can destroy the impeller .

If the boat is on a trailer:
Use a set of flush muffs (earmuffs) that fit over the water intake ports on your lower unit. Attach a garden hose, turn on the water FIRST, then start the engine .

Important: Some Mercury outboards (like the Verado) have a specific flush port that is NOT for running the engine — only for flushing with the engine off. Check your owner’s manual .

If the boat is in the water:
You can start normally, but still do a visual check that water is flowing out of the telltale (the small stream of water from the back of the engine).

The First Start Procedure

  1. Insert the kill switch lanyard. This is embarrassing to forget .
  2. Ensure the engine is in neutral.
  3. Turn on the battery switch (if equipped).
  4. Pump the primer bulb (on engines with a primer) until it’s firm.
  5. Turn the key.

The engine may take a few extra cranks to start after sitting all winter. That’s normal. Let it idle and watch the telltale — you should see a steady stream of water within a few seconds .

Let the engine idle for 10-15 minutes to burn off any fogging oil left in the cylinders. You’ll likely see some smoke — that’s normal .

Don’t rev the engine until it’s fully warmed up. Cold revving causes unnecessary wear.

Does water flow from the telltale within 5 seconds of starting? If not, shut down immediately and check your water supply.

Phase 6: Test Everything Else

With the engine running at idle, work through the rest of your systems.

Steering:
Turn the wheel lock to lock. It should move smoothly without stiffness or grinding. If it’s stiff, see the steering troubleshooting guide .

Tilt and Trim:
Run the engine up and down through its full tilt range. Listen for unusual noises. Check for hydraulic fluid leaks.

Bilge Pump:
Pour a bucket of water into the bilge area. The pump should activate automatically (if equipped with a float switch) and pump the water out. Then test the manual override switch .

Navigation Lights:
Turn on all lights — bow lights, stern light, anchor light — and verify they work .

Horn and Electronics:
Test the horn, fish finder, GPS, radio, and any other electronics .

Fuel System:
Check for any fuel leaks around the tank, primer bulb, and engine connections. Sniff for gas fumes before and after starting .

When did you last test your bilge pump? Pour water in right now — don’t assume it works.

Phase 7: Launch Day Final Checks

You’ve done all the prep. You’re at the ramp. Don’t blow it in the final moments.

Before You Back Down:

Install the drain plug. This is the most common — and most embarrassing — mistake boaters make. One experienced writer admits: “Yes, that’s four separate mistakes, but they all come under ‘most common boating bloopers.’ Don’t laugh, we’ve all been there before” .

Remove the trailer tie-downs. The straps holding the boat to the trailer need to come off before you launch.

Check the fuel tank vent. If your tank has a manual vent, make sure it’s open.

Attach a dock line. Have a line ready before you back down so you can secure the boat immediately after launching.

After Launching (Before You Drive Away):

Check for leaks. Look in the bilge area and around the drain plug. Any water coming in?

Let the engine warm up again. Cold starts are hard on engines.

Check the telltale again. Confirm water flow.

Test forward and reverse at the dock. Make sure the engine shifts smoothly.

Does your ramp have a courtesy dock? Use it. Don’t be the person blocking the ramp while you figure things out.

The “Don’t Be Stupid” List: 10 Spring Mistakes to Avoid

Based on years of boater confessions, here are the mistakes you really don’t want to make .

1. Forgetting the drain plug. See above. It happens to everyone once. Don’t let it happen to you.

2. Launching before sealant cures. Some below-waterline sealants (like 3M 5200) take seven days to fully cure. Splash too soon, and you’ll have leaks .

3. Changing spark plugs before the first start. The fogging oil from winter will foul brand new plugs immediately. Run the engine first to burn off the oil, then change plugs .

4. Waxing non-skid decks. You’ll turn your boat into a skating rink. Don’t do it .

5. Using acid-based hull cleaner on an aluminum trailer. The acid will eat into your trailer. Only use these products if the boat is on blocks .

6. Holding the buffer in one spot. You can “burn” the gel coat and leave permanent swirl marks. Keep the buffer moving .

7. Forgetting to open the fuel tank vent. The engine will starve for fuel and die.

8. Skipping the trailer light check. Fix them at home, not on the ramp shoulder.

9. Over-greasing trailer hubs. If you greased them before winter storage, leave them alone .

10. Starting the engine without water. This kills impellers. Don’t be that person.

Have you made any of these mistakes before? Learn from them — and from everyone else who already paid the price.

Spring Startup Checklist (Printable Summary)

Trailer
☐ Tires inflated and not cracked
☐ Wheel bearings spin freely
☐ Lights all working
☐ Brakes tested
☐ Winch strap and safety chains inspected

Battery
☐ Terminals cleaned and greased
☐ Fluid levels topped (flooded batteries)
☐ Fully charged
☐ Load tested

Engine
☐ Cowl removed, visual inspection
☐ Propeller inspected
☐ Water pump impeller replaced (if due)
☐ Engine oil checked
☐ Lower unit gear lube checked
☐ Belts and hoses inspected

First Start
☐ Water source connected (muffs or in water)
☐ Kill switch lanyard attached
☐ Engine in neutral
☐ Start and check telltale

Systems Test
☐ Steering operation
☐ Tilt and trim
☐ Bilge pump (test with water)
☐ Navigation lights
☐ Horn and electronics

Launch Day
☐ Drain plug installed
☐ Trailer tie-downs removed
☐ Fuel vent open
☐ Dock line attached

Post-Launch
☐ Check for leaks
☐ Warm up engine
☐ Test forward/reverse

Print this checklist and keep it in your glove box. You’ll never forget a step again.

FAQ: Spring Startup Questions Answered

What makes Avalon pontoon boats different for spring startup?
Avalon’s Reinforced Aluminum Pontoons have drain plugs that sit below the waterline — you must lift the boat or trailer it to check for water inside. The owner’s manual has specific spring commissioning instructions .

How long should I let my engine warm up before driving?
At least 5-10 minutes at idle, or until the thermostat opens and the engine reaches operating temperature. Cold revving causes unnecessary wear.

Do I really need to replace the water pump impeller every year?
Not necessarily every year, but definitely every 200-300 hours or 2-3 years. In saltwater, consider more frequent replacement .

What if my engine won’t start after winter storage?
Check the battery first (most common cause). Then check fuel (old gas? water in fuel?). Then check for spark. Work through the systems systematically.

Can I use my mooring cover for winter storage?
No — the Avalon manual explicitly states mooring covers cannot withstand snow loads. Use shrink wrap, indoor storage, or a heavy-duty winter cover .

How do I know if there’s water in my pontoons?
If one pontoon sits visibly lower than the other on the trailer, or if water drains out when you remove the bottom drain plugs, you have water inside .

Do I need a professional spring tune-up?
Not necessarily if you’re handy, but a dealer can run compression tests, check alarms, and catch problems you might miss. The warranty may require professional service .

Your Spring Action Plan

Here’s your timeline for the next two weeks:

This weekend:

  1. Inspect the trailer — tires, lights, bearings, brakes
  2. Remove covers and inspect the boat thoroughly
  3. Check and charge the battery
  4. Order any parts you need (impeller, filters, fluids)

Next weekend:

  1. Change the water pump impeller if due
  2. Check all fluids — engine oil, gear lube
  3. Inspect belts, hoses, and propeller
  4. First start (with water!)
  5. Test all systems

The day before launch:

  1. Final battery check
  2. Pack safety gear — life jackets, fire extinguisher, flares
  3. Check expiration dates on flares and extinguishers

Launch day:

  1. Drain plug installed (say it out loud)
  2. Tie-downs removed
  3. Dock line ready
  4. Enjoy your first day on the water

Safety reminder: After launching, always run the bilge blower (if equipped) for at least 4 minutes before starting the engine to clear any fuel vapors from the engine compartment .

Spring startup isn’t the most exciting part of boating. But it’s the most important. Do it right, and your first day on the water will be everything you dreamed about all winter — not a stressful mess of dead batteries, overheating engines, and tow trucks.

What’s your favorite Avalon boat feature or on-the-water experience? Share your thoughts in the comments below.

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