What grade of gas?

[schoolsout]

My JD dealer called yesterday about my mower and the problem was water in the gas. Now the question is how did it get there? I get all my fuel from a newer high volume station.

Ethanol is hydrophilic

Also, if a fuel tank is left more than empty, but less than full, the fuel will expand in the heat and condense at night when it cools...this pulls in moisture over time and water accumulates at the bottom of the tank.

 

[Soundguy]

yep.. vented tank and sump draw in air then it has condensation.. I like to keep tanks full when possible.

soundguy

 

[Grand_Pooba]

My JD dealer called yesterday about my mower and the problem was water in the gas. Now the question is how did it get there? I get all my fuel from a newer high volume station.

I picked up my tractor yesterday and had an interesting conversation with the mechanic. He told me when he dumped out the tank I had just filled that it was more water than gas. I think this goes beyond condensation...I believe I maybe the victim a really dumb practical joke.

 

[Diamondpilot]

I picked up my tractor yesterday and had an interesting conversation with the mechanic. He told me when he dumped out the tank I had just filled that it was more water than gas. I think this goes beyond condensation...I believe I maybe the victim a really dumb practical joke.

Had you just purchased this fuel? In the case of my neighbors power washer that I had to replace the carb on it was 50/50 water gas mix when I dumped it out. He had just bought the fuel a week before he had filled it but then let it set for some time so who knows. He was also using a metal gas can that was not full so it could have been a joke someone was playing or just simple condensation.

If you had just bought the gas I would find my receipt and take that along with the receipt for the work to your mower to the station owner. He should pay.

Chris

 

[Soundguy]

yep.. could be wet fuel.

gas pump don't know what it's pumping.

soundguy

 

[Gale Hawkins]

I picked up my tractor yesterday and had an interesting conversation with the mechanic. He told me when he dumped out the tank I had just filled that it was more water than gas. I think this goes beyond condensation...I believe I maybe the victim a really dumb practical joke.

I had an ag teacher tell about how proud his 5 year old son announced he had filled the car with gas for Daddy. On questioning his son he learned it was with the garden hose. :laughing:

What he did has stuck with me for 45+ years. Instead of beating or yelling at the kid he just went and bought a locking gas cap because the kid's intent was noble but wrong.

 

[DarkBlack]

higher octane does have benefits and pitfalls:

as was said, higher octane has a higher flash point, meaning it requires a higher temperature to ignite. this has been known to cause problems with hard starting and plug fouling in cold climates for some fuel injected and carbureted engines.

the benefit that goes with the higher flash point is a faster burn cycle. lower octane starts burning sooner, but the burn lasts longer. the quicker burn cycle of the higher octane means the combustion is completed faster, and there is less heat built up in the engine. simple version: slightly lower engine temperature.

with that lower engine temperature can come another issue: water cooled engines are generally designed to run at a certain temperature - often in the ballpark of the boiling point of water. by burning a higher octane fuel you are fighting the engine's fuel system.

personally, i will only use a higher octane for a couple instances: when the manufacturer recommends it such as performance / older vehicles, and in small air cooled engines. chain saws often take a lot of abuse in very hot temperatures, not to mention a very small engine turning 12k-14k rpm.

i have first hand experience with a carbureted snowmobile that fouled plugs on high test. i would have had to alter the plug heat range or re-jet to compensate. i have been around a fuel injected snowmobile that did not run well on high test because it could not get the engine temperature where it wanted to be. i have drag raced a snowmobile where running high octane aviation fuel allowed an insane reduction in jet sizes that did not melt the engine down because it kept it from getting too hot. i have also seen many vehicles with fouled plugs on cold mornings from trying to start on high test. i have heard stories of factory fueled high test vehicles not starting in the winter on dealer lots, but i can't back up that story.

My life's experience contradicts a lot of what you wrote. First of all both 87 and 93 will start burning at the same time unless you have pre ignition issues. That time would be when the plug sparks. The speed that the resulting flame moves across the face of the piston is effected as much by head chamber shape, and piston top shape, as it would be from octane rating. Both 87 +93 contain the same btu's. Flame heat makes cylinder pressure that makes HP. The exception to this is at very high rpm's a high octane fuel can still be burning as it exits the cylinder. Ignition timing set wrong could be a real culprit.
I've never seen a sled not be able to run at temperature because it had 93 octane gas. I've never heard of lots of new cars fouling plugs. Oil fouled 2 stroke yes. What I have seen personally is my 87 rated pickup getting 17mpg with 87 yet it gets 19mpg with 93. My 87 rated bike has less engine buzz/vibration with 93. and my fuel injected snowmoble starts and runs the same with 87 or 93.

 

[Scrambler82]

I didn’t read all of the post, too much but good input and these are my thoughts from time itself… 50 years of Mowers/Chain Saws/Weed Whackers and who remembers what !
I have only ruined two chain saws from old gas/lower octane, after using stabilizer and setting over the winter.

Now my opinion… when mixing oil with gas run the Super, the Unit will run cleaner, less carbon build up and overall better performance and never run stored gas. Throw out the gas at the end of the season and get new at season start. Rinse out the gas container before adding new gas if possible. If you are one of the lucky ones that lives in an area that you cut grass all year long, run the best you can get, it’s cheap.
If straight up gas, run one step higher in octane than prescribed by manufacturer or super if the middle or a selection is not available. Yes may be a little extra ($0.20/gal) but in the long run less carbon, cleaner burn once ignited.

If running the Motor all the time at full throttle a lesser octane gas will work and work well enough but if you store your tools clean’um up and drain’um out.

Thks for listening.

 

[Just Bill]

I think every one here would benefit from a little research about octane.
Some are close, some are in left field and some are not even in the the
ballpark.

 

[Soundguy]

My life's experience contradicts a lot of what you wrote. First of all both 87 and 93 will start burning at the same time unless you have pre ignition issues. .

that was my entire point. PRE IGNITION ISSUES.. like spark knock / PING.. or simply.. pre ignition. that's what higher octane is great for.

soudnguy