Originally Posted by noco
dude i am a mechanic...havent seen many problems from the fuel...your right though...fuel systems are meant for the added corrosiveness...i havent been able to see any marine motors though....i do live in colorado....not a whole lot of marinas here...i decided im not concerned about junking some parts...lets face it they really arent very expensive...i am really just concerned about the thing loosing its bottom end quickly...corrosion of the fuel system componants is not such a big deal to me...you do make a good point about the fuel in the crankcase but it is gonna be mixxed with oil...what have the outboard mechanics said about this???
To give you a bit of my background, I am a Harley mechanic, specializing on older models.
I have been working on all brands of motorcycles for 27 years.
The damage I have seen is:
Pitting of the float bowl and carburetor body (internal).
White oxide in the fuel and air passages of the carburetor body.
Brass Idle mixture fuel screw needles turning green, and altering the mixture.
The little o-ring that seals the above idle screw swelling and becomint a PITA to get out.
White plastic floats disentergrating into a kind of sandy, crumbly stuff.
The viton rubber tip on the float needle swelling up to near twice it's origional size. This is leading to lowering the fuel level in the float bowl,which can cause poor idling and high speed lean out.
Float bowl o-rings swelling up to the point where gas starts weeping around the seam.
Accelerator pump diaphragms deteriorating and getting pinhole leaks in only a few years instead of 10 or so.
White oxide dusting in the intake ports of aluminum heads.
Slightly green bronze (Ampco45) intake valve guides.
Factory applied gas tank liners blistering and sluffing off in chunks.
Kreem brand do-it-yourself tank liners turning into a thick, slimy muck inside the tank.
And that is just what I have seen in the past 5 years or so.
Before that all I really had to deal with was dry rotted or hardened seals, o-rings, rubber parts, or water damage due to a bike being left out in someone's backyard for years.
Now I am seeing all kinds of new problems in daily riders.
I am also seeing some very strange sparkplug deposits. I know what typical cheap gas station gas deposits looks like on a sparkplug, but now I am seeing, white, green or orange deposits, And not a fluffy deposit but kind of a prickly appearance?
The few folks I have talked to in the marine industry are seeing a sharp increase in rusted out gas tanks, diaphragm type fuel pump failures, hardening of fuel lines, and very corroded carburetors.
They have it worse as any type of ethanol absorbs water or water vapor. Think of where a boat lives.
Gas dryer, available in most any auto parts store, is mostly alcohol. Go ahead and read the label on one if they actually list the ingredients.
Used ocasionally, it does no harm.
This ethanol crap gas is a whole new ball game!