I nearly didn't manage to get the internet's Stationary Engine Mailing List contribution done this month thanks to two weeks of horrendous computer problems. When I finally got back on line and downloaded all the mail there was such a suitable-looking thread, that I abandoned my backup restorations and got to work! A contributor from Canada, for whom thoughts of winter come early, began this thread, and the replies reflected, to a certain extent, the geographical variety of contributors.

* Since things seem quiet I was wondering what the general opinion was on draining fuel tanks for the winter on gas engines. I have always done it, then started out in the spring with fresh gas but some people tell me they don't bother etc. Thoughts?

* In my opinion, nothing serious will happen if you let untreated gasoline sit over the winter. I have, however, encountered some difficulty with engines stored for a few years.

* I'm not sure about modern gasolines, but a few years back I had to get a motorcycle going that had been in storage about five years. The gasoline shutoff valve gradually leaked fuel into the carbs where it evaporated. The resultant varnish had built up to 3/16-inch thick in some places; came close to having to throw both carbs into the trash pile.

* I've also come across engines that had dried varnish completely plug up the gasoline lines, check valves, etc. Of course they had been stored for years.
Bottom line: Over the winter, don't worry about it. Long-term, drain.

* One argument in favor of draining is that next season you may be favoring other engines in your collection and that one doesn't make it out to play. Then it moves furthur back in the shed and misses another season. Pretty soon it's five years later and the tank is filled with stinky goo.

* I always drain fuel tanks for the winter, another reason being that my insurance company wants it that way. I have to store the fuels in a separate little store box outside the shed.

* We just bought a home in Florida that came with a riding mower (12 HP Briggs) that hadn't been run in over two years. The original gas was still in it and the gas can was about 3/4 full and un-capped.
I fully expected to have fuel system problems with it but, once the battery was charged (even it took a charge and holds it!!), it started right up and ran fine.
After two mowings of the yard, it ran out of gas so I just poured the two year old contents of the gas can into it and finished mowing. No problems!
Now, I guess that when I put fresh gas into it, it will decide (a'la Murphy) to make life miserable!
That's not to say that I advocate long-term storage without draining the gas - I seem to have been lucky in this case.

* I've never bothered, and so far haven't encountered a problem. The little two-stroke engines in things like weedeaters and chainsaws have started right up after as much as 10 years of nonuse, just adding fresh fuel. I did find a Briggs & Stratton a bit "cranky" on the first tank of gas, which had evaporated down to maybe 30% of its volume, very sour stuff. I'd just topped it with fresh gas. Primed it with a splash of fresh gas in the carb to get it started, and it was fine.

* Two cycles, especially the richer oil mixes, can be a problem when trying to start after a layup. The fuel evaporates and leaves the heavier stuff that's not very volatile, making for hard cranking.

* I've never had a problem in not draining fuel tanks over the winter. However, I have encountered a stale smell in the gas if an engine is going to sit for 2 or more years. I have a few Briggs that sit and get forgotten.
Mostly, I've been lucky.

* I would be more concerned with the fuel bowls on carburetors of small engines and lawnmowers. I guess you should drain the tank, then run the engine out of fuel.

* Over the years I've dealt with too many springtime hard starters. The gas can I use for all outdoor power equipment never gets filled without putting Sta-Bil in it first. That's the same gas can that I use to fill my old engines with. I use gas from it to mix all my two cycle gas too.
So, I don't drain anything, I fill the tanks up for the winter!
The last time I needed my generator it had been sitting in my wide open garage for almost two years. It started first pull. I use it on all mowers, tillers, chippers and I can go out in the spring and everything starts up like I used it last week.

* STA-BIL works really well as long as you fill your tank FULL.

* I don't drain the fuel tanks, but as autumn approaches, I start treating my fuel purchases with Sta-Bil. It doesn't cost a lot, no more fuel than is involved, and that way I don't face spring with tanks, carbs, mixer, etc full of gum. The last time I forgot cost me $75 US for a totally wrecked chainsaw carburetor, tank and engine. No trouble remembering since.

Needless to say, the following comment is from Australia, where engine show season lasts all year round!

* I make sure the petrol engines are empty if they are going to sit for a while, even if it is only going to be for a few weeks. Modern unleaded fuels seem to go off pretty quick and I will not even think of putting LRP (lead replacement petrol) in any of my engines. It goes off quick and fouls spark plugs like crazy.
My 12hp R&V will not even fire unless I put fresh fuel in it and I know of a few other people with ignitor engines who have found the same thing.
I cannot see how you guys (and gals) can cope with having to put your toys away for a few months every year. I would go stir crazy if I go for more than a week without running an engine and more than a month without going to a good engine display.

* If you think you have a fuel gum up problem in any engine go buy some racing fuel and put it in your tank. This fuel will clean up any varnish that has occurred. I have used it on occasion. I used it by mistake once in an engine in the crawler that I had sitting for time. The boys and I just got back from a mud run and I wanted to start the old engine. No regular gas around so I grabbed the fuel for the race truck and thought what the heck? and used it.
It ran really rough at first and then started leveling out. Took the carb off just to look and it cleaned up on its own.

* On the subject of sour gas, has anyone noticed that 2 cycle gas mix does not seem to go bad nearly as fast as straight gasoline? I usually mix up a 2 gallon batch of 32:1 for the weedeater about once a year. Never seems to go bad even at the end when I empty the can. Is is possible that the 2 cycle oil acts as a fuel preserver? I have used this mix in
the Hercules and am considering going to it on all the engines because of the long lasting qualities. Seems the top cylinder lubrication of the mix would be useful too... Any comments?

* I've thought the same. I think that 2-stroke oil helps to keep the gum from solidifying as the gas evaporates. Makes sort of a grease instead. Lots of people can tell you it doesn't always work, of course.

With luck, this article will reach the GEM readership before all your preparations for winter storage are complete. Of course, don't forget to drain your water hopper - freeze cracks are a lot more difficult to repair than cleaning stale fuel from a tank.


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