Daveís Marine and ethanol fuel.
I have looked for an article that could explain why your marine engine is having trouble performing the way it used to, I canít find a good simple explanation, so Iíll do my own.
10% ethanol blended in fuel was mandated by Congress in late 2006 since then some states have used their own judgment as to how much ethanol to allow.
Most modern marine engines ( 5 years and newer ) will operate on that fuel blend as long as itís not above 10%, However some precautions are necessary; Mercury Marine recommends their fuel stabilizer ,and fuel system cleaner be used with every fill up.
Ethanol in fuel is hydroscopic; that means it will absorb water directly from the surrounding air, when the ethanol has reached saturation it will phase separate and deposit water in the fuel tank. Your engine will pick up this water and can cause sever damage to not only fuel parts but the engine internal parts.
We have found that carburetors on older engines are especially affected by this fuel, a gummy resin will form in the fuel bowl, and that will clog low, and high speed jets, causing the engine either not to idle or run wide open throttle. The only way to clean the carbs is to dissemble them and soak them in a cleaning agent.
Modern fuel injection systems are less susceptible than the older carburetor engines to gumming because the fuel system is closed, however water ingestion will damage the internal injection parts, a small micron water separator is recommended to forgo these problems.
Modern gasoline blends should never be stored for long periods of time sic; two to three weeks. If your boat is going to be out of service for that length of time, be sure the tank is 7/8ths full and has the stabilizer added to it.
Symptoms of e-10 fuel problems; Engines may be hard starting or may not start if small fuel passages are clogged, acceleration may not happen, stalling upon acceleration, and or complete dying of the engine may occur. The engine may start well and run fine while itís cold, but after a short time of idle or stopping it may be flat or not run at all.. A common occurrence is ďVapor LockĒ, fuel pumps will not pump vapor, after sitting hot for a while the engine heat soaks ( getís hotter) this will boil off the fuel in the pump and or carburetor so that the engine will fail to start, or die off after starting. This problem can occur while under way, bubbles will form in the fuel line and cause a rough running or stalling condition.
What can you do to prevent this? First of all call your Congressman, ethanol has never been proved to save anything either cost ,or pollution.
Add Mercury Marine fuel stabilizer, and Fuel system cleaner to every tank, keep your tank full or nearly full when stored, disconnect the fuel line on outboards and let them run dry before pulling out of the water, allow an inboard engine to idle for a time before shutting it off, and allow it to idle for a while after starting hot. These few things will help, but not cure.
If you have any further questions please do not hesitate to call one of the techs at Daveís Marine ! 740 423 6541
Daveís Marine and ethanol fuel.