Picture this: you walk into the shop and spot a mysterious bottle of murky, questionable liquid sitting on the tech bench. Is it a new experimental energy drink? A mystery cocktail? Nope—it’s something far more common and far more dangerous to your boating season: contaminated fuel.
If your instincts screamed “bad gas,” you’re absolutely right. And if you’re a boat owner, this should be your cue to pay attention—because nothing ruins a beautiful day on the water faster than engine problems caused by old or dirty fuel.
Why Fuel Matters More Than You Think
Boats are not your average vehicles. They often sit for long periods between uses—especially in places like Maine, where boating is seasonal. This downtime makes them especially vulnerable to fuel degradation and water contamination in the tank. And when that happens, it’s not just a matter of inconvenience—it can lead to engine damage, lost time, and expensive service bills.
So the question becomes: how do you know when to use a fuel stabilizer, when to top off with fresh fuel, and when to siphon it out and start over?
Let’s break it down.
🚫 When in Doubt, Siphon It Out
If you suspect your fuel is old, smelly, or discolored, don’t take chances. It’s always safer (and cheaper) to siphon it out than to risk it running through your engine.
Old or contaminated fuel can cause:
- Hard starts or no starts
- Engine misfires
- Stalling
- Clogged injectors or carburetors
Save yourself the headache. Drain it. Dispose of it properly. And refill your tank with high-quality fresh fuel from a trusted source.
✅ When to Use Fuel Stabilizer
Fuel stabilizer isn’t a cure-all—but it’s a valuable tool. If your boat is headed into storage for the winter or sitting idle for more than a month, stabilizer helps slow down the fuel’s degradation and prevents phase separation (when ethanol and water separate in the tank). It’s a smart choice when:
- You're winterizing your boat
- You’re storing it between infrequent summer outings
- You want to extend the usable life of existing fuel
Just remember: stabilizer doesn’t reverse bad fuel—it just delays the breakdown of good fuel. If the gas is already questionable, stabilizer won't help.
⛽ When to Top Off with Fresh Fuel
If your fuel looks and smells okay—but you know it’s been in the tank a while—you may be able to dilute any mild degradation by topping off with fresh, ethanol-free or high-quality fuel.
This works best when:
- You have a low tank (under 1/4 full)
- There are no signs of water contamination
- You plan to run the engine soon and burn it off
The key here is proactivity. Use the opportunity to cycle through your fuel regularly—once a month is a good goal during boating season.
Don’t Let Bad Fuel Sink Your Summer
Boating is supposed to be fun—not frustrating. If you’re unsure about the condition of your fuel, play it safe and take action early. And if you’ve already run into trouble, don’t worry—we’re here to help.
At Clark Marine, we’ve seen it all—from cloudy mystery gas to full-on gummed-up fuel systems. Whether you need a full fuel system cleanout, help diagnosing engine problems, or just advice on storage and maintenance, our expert service department is ready to get you back on the water.
Final Tips for Healthy Fuel Habits:
- Use stabilizer before storing your boat
- Run your boat regularly during the season
- Use high-quality fuel from trusted sources
- Don’t let your tank sit full of fuel for months at a time
- When in doubt… yep, siphon it out
Need help or have questions? Call us or swing by the shop—we’re always happy to help keep your boat running strong and your summer stress-free.