Quicksilver Quickleen Engine and Fuel System Cleaner - Keeps Engines

In this review the Quicksilver Quickleen Engine and Fuel System Cleaner is assessed for small outboards and gasoline engines that suffer from carbon build-up and occasional knocking. The bottom line: this treatment is best for owners who want a convenient, regular maintenance additive to remove deposits from injectors, carburetors and valves, and to help prevent piston seize-up. It stands out because a single ounce treats 5 gallons of fuel, making it an easy-to-use, economical option for routine care of ethanol-blend and regular gasoline engines.

Key Features

• Gas treatment and injector cleaner: formulated for use with all grades of gasoline and ethanol-blend fuel to maintain cleaner fuel systems across fuel types.
• Thorough carbon removal: quickly removes carbon deposits from carburetors, injectors, intake valves, spark plugs, piston crowns and cylinder heads to restore performance.
• Prevents engine damage: helps prevent engine knocking and piston seize-up by keeping combustion components clean and free of harmful build-up.
• Easy dosing: one ounce treats 5 gallons of gasoline, which makes it simple to add at every fuel tank fill-up or as part of regular service intervals.
• Suitable for outboards: customers report improved performance on small outboard motors, including 50HP Merc engines, showing practical real-world benefits.

Who It's For

Quicksilver Quickleen is aimed at boat owners, powersports riders and motorists who run gasoline engines that may be exposed to ethanol blends and want a straightforward way to reduce carbon deposits. It is particularly useful for people who perform regular maintenance and prefer adding a measured dose at each fill-up to maintain fuel system cleanliness.

Those who should look elsewhere include users who need a multi-purpose oil additive or a heavy-duty shop-grade engine rebuild product; Quickleen is a targeted fuel-system treatment rather than a lubricant or mechanical repair solution.

Pros & Cons

Pros

• Effective at restoring smoother running and improved fuel efficiency when used as directed, according to customer feedback.
• Convenient small bottle size and dosing rate of 1 oz per 5 gallons, making it easy to carry and apply at refueling.
• Works with all gasoline grades and ethanol blends, offering broad compatibility for mixed-fuel use.
• Good value for routine maintenance compared with more invasive cleaning methods.

Cons

• Some customers reported leakage issues with the bottle, so care is needed when storing and transporting the product.
• Not a substitute for mechanical repairs if the engine has severe damage or worn components.

Specifications

Product name	Quicksilver Quickleen Engine and Fuel System Cleaner
Use	Gas treatment and injector cleaner
Fuel compatibility	All grades of gasoline and ethanol-blend fuel
Dosage	1 oz treats 5 gallons of gasoline
Primary benefits	Removes carbon deposits, prevents knocking and piston seize-up
Manufacturer part number	8M0058681

Our Verdict

The Quicksilver Quickleen is a practical, cost-effective fuel system cleaner for routine maintenance of gasoline engines, especially outboards and small motors. It delivers clear benefits in deposit removal and smoother running when used consistently, and its simple dosing makes it good value for owners seeking to protect performance without major service work.

Frequently Asked Questions

Can this be used with ethanol-blended fuels?
Yes. The formula is compatible with ethanol-blend gasoline and all grades of gasoline.

How much product do I add per tank?
Add 1 oz of Quickleen for every 5 gallons of gasoline as the recommended dosage.

Will it fix a knocking engine permanently?
It helps prevent and reduce knocking caused by carbon deposits, but it will not replace required mechanical repairs if knocking is due to severe engine wear.