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Gas Tank
Posted by: aj_ed ()
Date: January 12, 2020 05:45PM

I am going to replace my fuel tank because I am getting a greyish sledge in the carbs (Weber 40IDTP). Before re-installing my original tank, I had used liquid carb cleaner with 1/4" nuts, shake and rinse method. looked clean, and clean gas came out when pumped out. I am running a pre-filter in front of the forward fuel pump, another filter before regulator, and the 4 filters in the Webers.
The engine ran great at first, then wouldn't idle. Pulled carbs to find sledge in float bowls. All filters didn't show the sledge in them. I was thinking water in fuel, but feels gritty.
Any imput?

Thanks, Ed
1965 Corsa 2nd owner since 1970

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Re: Gas Tank
Posted by: MattNall ()
Date: January 12, 2020 06:33PM

If filters are clean tank is fine!

Pull the carbs and do an ultrasonic cleaning..

US Cleaners have gotten Cheap! 7.5 Gal. for $99 []

3 gal. $39 out of Milwaukee, Wi.

Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!

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Re: Gas Tank
Posted by: JimBrandberg ()
Date: January 13, 2020 05:24AM

It has to be something from somewhere. It could be something from the tank or something in the gas or something in the lines or something from the carbs.
Usually the tank is due to rust which isn't greyish sludge.
Sometimes someone has coated the inside of the tank and something in the gas causes that coating to disintegrate. I had trouble with motorcycle tanks in the 80s and have shied away from coatings ever since. You never know what chemical from hell they might try to blend in the gas next in order to stretch out the corn squeezings or whatever. Nothing like dissolved epoxy in your carburetor or combustion chamber to foul things up especially if it gets melty.

I've run into bad gas that has visible crap in it like you're experiencing.
I've run into bad gas that looks and smells fine but burns poorly.

It's hard enough to determine what a greyish sludge may be in person, much less from here. I wish I could be more helpful than the general things I've brought up. If you could identify what it is maybe...

Carb cleaner is a general term. Some are made to rinse off with hot water and some are solvent based.

It looks like Weber 40 IDTP is similar to Weber 40 IDA 3-barrel. I'm jealous.

Jim Brandberg
Isanti, MN

Edited 1 time(s). Last edit at 01/13/2020 05:26AM by JimBrandberg.

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Re: Gas Tank
Posted by: 2manyvairs ()
Date: January 13, 2020 09:06AM

Drain some gas out of the tank at the front hose that connects to the sender outlet to see if it's coming from inside the tank?


1960 700 sedan - blue, #1819 oldest existing non horn slot car
1962 Monza sedan - black w/red cloth interior daily driver
1962 Monza coupe - silver blue/blue 4spd
1963 Greenbrier - standard, "Turdbrier"
1963 Monza cvt - Ivy Green/Fawn It's NOT red !!
1964 Monza coupe - red/black, 95hp pg, 54k miles 3rd owner
1964 Spyder cvt - Blk/Red It's NOT red either !!
1965 Monza ht - retired daily driver, the storage shed
1965 Corsa 140 ht - all good except for how it looks.
1965 Corsa 180 cvt - perfect body, everything else shot
1966 Corsa 140 ht - Red/Red, Canadian w/factory headrests, wood wheel, rr speaker, & oil bath,

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