How can I clean the old varnish in my gas tank

[rodbolt]

hello<br /> pump it down as low as it will go and add 2 to 3 cans of yamaha combustion chamber cleaner. seafoam may work let it sit over night. make sure you use a good fuel water seperator filter, refill the tank and try it.

 

[Old No 7]

How can I clean the old varnish in my gas tank

I have a 1988 boat with a 21gal tank, and an 88HP 2 stroke outboard. I have rebuilt the carbs, but still have issues starting it. A local mechanic is saying that the additives in new gas (I live in NY)are eating away at the gunk in my gas tank, and getting through the filter to my carbs. I was skeptical until a friend who just put a new fuel injected 200HP motor on his 15 year old boat had to have his injectors cleaned. His mechanic said the same thing and recommended a company that will clean the tank for $300.00.<br /><br />This is my first boat, first season. I can't find any posts on this here. Can this be true? Is there something I can use to clean my tank?<br /><br />I have already pumped it out as much as I could in August when I rebuilt the carbs.<br /><br />Thanks for the help, and Happy Thanksgiving to all!

 

[Winger Ed.]

Re: How can I clean the old varnish in my gas tank

I had a tank so fouled I had to drain it, and clean it out. Mixing and dissolving the goo into fresh fuel was out of the question, it was so bad. <br /><br />I drained it as best I could, then put a gallon of Lacquer thinner in it. Then sloshed it around, reached in with a rag on a steel rod and scrubbed the tough spots. <br /><br />Then caping the filler hole, and blowing air into the vent, pushed the mess out the outlet line.<br /><br />I Rinsed and repeated the flushing/scrubbing with a gallon of fresh gas & a pint of B-12 carb. cleaner 3-4 times before it looked OK. <br /><br />Ed.