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A lot of corrosion... fuel pump

J

juryduty

Member
Hi guys, I was up at my boat this weekend and noticed I am getting a ton of white, powdery corrosion from somewhere. What exactly is this stuff?

I have dual 1976 Crusader 220's and replaced the fuel pump on the starboard side only last summer, yet I noticed today it is already venting gas in the sight tube and the engine is running super rich (white smoke and needs the throttle way open to idle). The fuel pump seems to be covered by this white corrosion... help! Boat is in brackish water near the SF bay.

Pic attached.
 

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It's corrosion all right. I find that, with my boat stored for the winter, I get all kinds of nasty stuff like this if I don't leave the engine hatches open.

Jeff
 
That's more corrosion than I had in salt water 24/7. The difference being you see major temperature changes probably wetting down all the metal every nite?
 
super rich usually yields a black smoke....white smoke indicates coolant burning in the cylinders....

That is a lot for less than a year...painting the new one will help slow it down as will a corrosion guard spray on product when you 'store it' for the winter.

When you get the new pump installed, you may want to check for a leak while the engine is running....
 
Is it probable that the corrosion is the cause of the fuel pump failing so quickly? I just replaced it 3-4 months ago and have put maybe 5 hours on the engine since then.
 
Looks like you have fuel in the sight tube in the posted pic...that indicates the diaphragm has ruptured and that should be completely independent of the corrosion...

You may want to check the shaft seal on the raw water pump as a potential leak source..
 
To stop the surface corrosion you either need to paint the new part before installation (they sell cans of "Crusader Blue") or spray the part with T-9 (available at most marinas) which leaves a waxy, anti-corrosion coating. I agree with Mark that the diaphragm failure is an independent issue.

And you should look for a salt water leak that is exacerbating the situation. If it gets on your fan belt pulleys you will get corrosion that will eat up the belts. And they always fail when you are farthest from home. I know.
 
..."And they always fail when you are farthest from home. I know. "

Too true! My old RV ate an ignition module about 2 miles from our planned, furthest distance from home!

Jeff
 
Wait a minute... you mean saltwater leaking into the bilge could cause this? That doesn't seem to make sense... just some saltwater sloshing around in the bottom of the engine area? There is actually a lot of saltwater in there coming in from the shaft seals, which drip normally (couple of drips per minute).
 
OK here's something strange. I took the fuel pump home and took it apart to see what a ruptured diaphragm looked like. Turns out.. the inside of the pump is just fine.... and the hose barb for the "sight tube" doesn't actually lead anywhere. It is closed off inside the pump. This is a Sierra 18-7270.

Now the question is -- I saw fuel in this line, and it clearly did not come from the pump. Is it possible for the carb to eject fuel into this line from the other end (I did see it at both ends)? Or maybe it is condensation?

fuel_pump_apart.JPG
 
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The port for the sight tube should lead to the chamber formed by the diaphragm...

The carb end of the sight tube path leads straight into the primary venturi area so, if the carb if functioning ok, the answer is no, fuel won't be ejected into the sight tube from the carb. condensation - maybe but the ID of the liquid should have been pretty obvious when you cut the sight tube...
 
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