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Contaminated Fuel

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dcbullington

Contributing Member
"Started having trouble with t

"Started having trouble with the port engine not being able to go above 2500 rpm (less than 50 hrs on both 327F's) so I checked the fuel filter and there was a ton of what looked like some sort of fungus, along with a fair amount of either sand or scale. I have a 1966 Cavalier with galvanized tanks. When I replaced the filter, she ran great for about an hour and then the same problem (only the port). This time she stalled coming into the dock and wouldn't re-start (got to practice single engine docking technique!). Drained filter, got a bunch of the same fungus looking stuff. Started right up, but I also noticed a lot of semi-burned fuel floating on the water near the port exhaust. Not sure what the significance of this is. My question: should I just run it and keep cleaning the filter until I burn through the bad gas, or pump it all out (about 50 gal) and clean out the tank or maybe replace it?

Thanks for any comments/help.

Dave"
 
"Welcome to the wonderful worl

"Welcome to the wonderful world of ethanol.

The safest thing to do is to drain & clean the tank and refill with fresh fuel. I'd expect the same symptoms to develop in the other tank(s), if you treat all of them the same. You're most likely seeing the 'cleansing' effect of the ethanol. It could be phase separation but doesn't sound like it.

You can buy a case of filters and run the fuel if you want to. The risk is that you can't control when the filter is gonna 'fill up' with the fungus."
 
"Update: Removed both pick ups

"Update: Removed both pick ups from the tanks and siphoned off about 10-15 gal from the bottom of each tank, couldn't believe the gunk and water I got out of there! Replaced fuel filters and took her out, everything is great except the port engine doesn't want to idle and there is quite a bit of white smoke coming from that exhaust. I'm thinking the carb is clogged up and it still may have some water in the floats.

Dave"
 
"You won't have water in t

"You won't have water in the floats; maybe a touch of fuel.

Possible some of the crud has made it to the carb. Only way to tell is to take it apart and see.

White smoke isn't a good sign, especially with FWC. How hot is the port engine? compared to starboard?"
 
"Port isn't running any ho

"Port isn't running any hotter than starboard, both around 140 at 3000 rpm, both drop to 120-130 at idle."
 
"would the exhaust be better d

"would the exhaust be better described as steam vs white smoke?

Temps look ok so I'd bet the smoke isn't from coolant but more likely steam (which isn't bad).

Very possible carb bowl has water in it. Any that makes it past the filter will settle in the bowl. Then it sits in the bottom and...well, it gets ugly as time goes on.

Lot of gents swear by SeaFoam (search and you will find lots of postings); maybe be worth a few cans."
 
"Update:

Drained both fuel

"Update:

Drained both fuel tanks (got a ton of goo, sand, junk out of the bottom of both tanks) and re-built the port carb (stbd has been running great) and still have white smoke coming from the port engine. I'm convinced it's steam but not sure of the source. It is present at idle and only increases when you increase RPM's. No overheating going on. These engines have less than 30 hrs on them so unless the crap I sucked into the port engine caused some kind of damage, I am at a loss to explain where/why the port is steaming so much....also concerned about taking it out to test under load until I know what's going on and that I won't cause more damage.

dave

p.s. when I had the carb re-built, the carb shop told me there were some incorrect parts installed and they were surprised the carb worked as well as it did. It's been re-built to the correct spec's now and seems to idle fine but as I said, I am reluctant to take it out until I know the cause of the steam."
 
Dave:

Sounds like a lot of

Dave:

Sounds like a lot of work but worth the effort.

do these have HX or raw water cooling? D you have an IR temp gun?
 
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