I have a 1981 18 foot Donzi with a big block in it. This year all of the sudden every time I take it out the smaller filter at the carb keeps getting clogged. Yesterday when I took it out it would die at high RPM's as well as would not idle. It seemed to be starving for fuel again so I assume the same thing has happened or the canister filter may be clogged as well. What it looks like is the shalac from the old gas that was built up on the side of the tank is now coming loose? It is a brown powdery substance. Does anyone know the best way to deal with this? Additives?

Thanks
Jon

you've figured it out...ethanol is a solvent and is removing 30 years of buildup from the insides of the tank. If you don't want to remove it one fuel filter at a time then you'll need to have the tank prfessionally cleaned, hopefully getting it all at once!!!

I hooked up an electric fuel pump, with a filter, and cycled the gas from the tank to the filler neck................Many times, cleaning the filter every 10 gallons or so, seemed to work.

Audiofn, Look on the DONZI REGISTRY someone had the same problem w/old gas in tank--he used some solvent to remove biuldup. I have a 16' DONZI BABY O/B, we should get together some day, possible for the CONN RIVER RUN. Michael "HIGH LIFE"

Michael I keep it up in Maine. There are a few of us up there now. Couple 18's and a 16. I had hoped this was going to be the more "economical" way to boat then the Formula this year but it has been painfull. I will take a look at that other thread over on Donzi.net. Thanks.

I had a similar issue with an old gas tank in a classic Mustang. Ran a couple of full tanks with Seafoam in them, cleaned the varish out - no more clogging filters.

I had a different problem with ethanol...water which several of my friends experienced. After cleaning up the carbs and replacing the filters...baby purrs like a kitten. I also use "ethanol medic", one quart ($20) treats 500 gallons of gas. Stabil also makes an additive for ethanol.

Startron makes a good additive for ethanol. They also have a tank cleaner product too.

if your tank is clean and dont have any problems fuel related is there a reason to run the (ethanol medic or stabil) ???

My first use of a octain booster this year all my black floats in my new quick fuel 850's lost the epoxy that holds the weights in so I replaced them with brass, not sure if it was the ethanal or the boaster
Rich