Gas Tank Question.....

When I bought my 88 model yamaha 25hp motor, it came with a 6 gallon metal gas tank. Buddy of mine told me the first thing to do was to trash the metal tank, and get a new plastic one. Told me the metal tanks over time corrode and gum up the carbs on the motor. I shined a light inside the tank, and it looked to be in good condition. Should I replace it or not? Already waaaay over budget on this project, and dont want to spend more than I have to...Thanks Joe

I've run metal tanks for years with no problems.Just make sure you keep the water out. =D>

Unless there is something wrong with the metal tank keep using it.

Use it until you can get a plastic tank - your buddy is correct, but as long as it is good you can use it.


Look for a used plastic tank - they are everywhere. I found 2 nice tanks floating down the river one year

Your buddy is off the mark on his knowledge of fuel tank material. A steel tank will not create any issues. An aluminum tank, with today's gasoline may create issues although if you run ethanol free gasoline then you are good to go with aluminum as well. I run only steel tanks and will continue to do so. The steel retains it's shape unlike a plastic tank...which roughly turns itself into the shape of a football when hot. That, in my opinion is not a desirable benefit of any fuel tank. Second, almost all of the current fuel issues we face are the result of the use of ethanol extended gasolines, not of fuel tank material. Point blank, todays gasolines are junk for any marine engine and fuel system and you constantly have to be on the ball to run standard pump gasoline sucessfully on a prolonged basis. Rather than put up with the hassles of constantly changing out primer bulbs, hardened fuel lines, deformed carb seals, rebuilding fuel pumps (look how many failed fuel pump threads are on here at any time) and gaskets and checking fuel for water I also run only ethanol free fuel in all my outboards and lawn equipment. Zero issues.
You will find that the hidden costs of running ethanol fuel has significantly risen in the last couple months. EPA has mandated (and these mandates are now in effect) that all flexible fuel system components have to now be made of materials that will contain fuel vapors from permiating through the walls of the fuel system. This has led to new fuel line prices in excess of $5/ft. and quality primer bulbs you almost have to take out a loan for. An example: Yamaha's plug and play portable fuel line assembly which consists of the fuel line, primer bulb and the ends now retails for around $75 !!

How do I know if the fuel I get is ethanol free? I see stickers on some pumps telling what percentage it is, but I never really paid much attention. Is this something that HAS to be posted in plain view stating that it contains ethanol? State or Federal mandate on the notification of the public? Thanks Joe

The tank will be labeled in most if not all states. Retailers typically make a big deal out of carrying ethanol-free gas. You can always ask at the local marine supply dealer or ATV dealer, and many states list those selling ethanol-free fuel on their website...go to the department of transportation home page.

Or try www.pure_gas.org and see if you have one near you. That site is handy but not necessarily updated as well as it can be.

I have a 1988 Mercurey and have been using it for years and no problems, YET

Not sure about other parts of the US, but here in SC, nearly every marina carries ethanol-free fuel. That's because they understand the problems associated with ethanol based fuel. Some gas stations also carry it, but you have to look around for them.

Also, you should be aware that ethanol-based fuel is 30% LESS EFFICIENT than MTBE-based fuel (non-ethanol) That means 30% less horsepower, 30% less gas mileage. It really is crap, and folks should avoid buying it, let's use the corn for our food supply, instead of burning it in our gas tanks.

Finally, you should avoid mixing MTBE and ethanol fuel in the same tank. If you're running MTBE, stay with it, if you're running ethanol, stay with it, or be ready to completely drain the fuel system before adding MTBE fuel. And remember that when you add "Sta-Bil" to your fuel, you use the RED Sta-Bil for MTBE, and the BLUE Sta-Bil for ethanol fuel, ONLY. Do NOT use red sta-bil with ethanol fuel, it will turn to pure junk.

Metal gas tanks are not the problem, metal doesn't create anything except rust. The gasoline will leave varnish, which can and will plug up your carb. Ths simple solution is to empty your gas tank when your not going to be using it for extended periods of time.

My gas tank was built in 1957, and I still use it.