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My lawn mower died AGAIN !

Post in 'DIY and General non-hearth advice' started by Pallet Pete, May 3, 2013.

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  1. nate379

    nate379 Guest

    How do you like getting fumed out with the AV gas? I ran a gallon or so in my ZTR mower when I had just a bit of mowing left and I was out of regular gas. I could smell the fumes off it for weeks and several tanks of fuel later. Dunno why?!

    Running 100LL in stuff not designed to run on it is actually pretty rough on the motor.

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  2. TMonter

    TMonter Minister of Fire

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    Actually when you pull a motor apart that has been run on AV gas versus standard gas apart you can tell very little difference if any. Are you sure it was AV gas it was smelling? AV evaporates cleanly compare to standard gas.
  3. blades

    blades Minister of Fire

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    old alky gas is only part of the problem, the other part is everything is set so lean to meet emmision standards coupled with the alky fuel already runing hot, just plain melts them down. Part prices have always been nasty for the most part. I remember a poster of a Honda Accord in an insurance office, if you bought all the pieces individually the car would cost close to 5 times it msrp.
  4. Badfish740

    Badfish740 Minister of Fire

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    My (retired) dad does a good business picking up dead equipment at the curb, making usually minor repairs, and reselling it. For folks who don't have the first clue how this stuff works, once the mower doesn't start, they basically have two options-get it fixed or buy a new one. Most small equipment repair shops these days really make their $$$ servicing "fleets" of mowers, trimmers, and the like for landscapers, farms, rental outfits, and construction companies as well as dealing in high end lawn equipment. When joe blow homeowner walks in and needs his Home Depot special 6.5HP self propelled mower fixed they say "Sure-here are our labor rates!" At that point, joe blow homeowner puts his mower back in the trunk, and heads to Home Depot to buy a new one, stopping by the house on the way to put the mower out for trash. ;lol My dad then picks it up, cleans last year's varnish out of the carb, changes the oil, shines it up, and puts it out for sale in front of his house for anywhere from $50-80 depending on the type of mower. This time of year he can barely keep up with demand.
  5. nate379

    nate379 Guest

    No that is not correct at all!

    100LL is a very dry fuel. Reg gasoline has some lube qualities to it. We can call this "top end lube". Run just 100LL in an engine not designed to run on it and you will end up burning it up.
    Also 100LL is designed for engines that run at about 3500 rpm constantly. (piston engine aircraft) Running it in a higher RPM application can cause slight amounts of detonation even though it has a higher octane rating because the way it burns.

    I run a mix of 100LL and high test gas in my race car. The 100LL raises the octane to keep my timing from being pulled (knock sensor) and the pump gas serves as a lube. Usually run about 50/50. I'd run race gas but it runs about $9/gal where 100LL is about $5/gal. Plus much easier to get 100LL, there is a pump not even 1/2 a mile from my house.

    I think a few folks have been watching too much TV where the characters fill their car on 100LL and all of sudden it goes from 100hp to 600hp :rolleyes:

  6. Badfish740

    Badfish740 Minister of Fire

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    I haven't priced it lately but back when I was into turbo'ed 4 cylinders I used toulene bought from paint supply stores to boost octane. I got the recipe from a Porsche enthusiast site-they have the formulas where you plug in the ratio of toulene to gasoline at what octane and what you'll end up with. They recommended adding a small amount of ATF as upper cylinder lube.
  7. TMonter

    TMonter Minister of Fire

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    That can't be right. Detonation is a function of vapor pressure and octane basically indicates the resistance to detonation typically through the additive package. What RPM you run at should have very little to do with it since detonation is driven by the compression ratio and vapor pressure of the fuel.

    Airplanes do run around 3500 at cruise not certainly not all aircraft and not during part load and takeoff/landing conditions.

    If 100LL were as poor about lubricating the engine as you say there is no way they would use it in aircraft. In fact the lead in AV gas being a lubricant is the primary reason it is there.

    Note I'm not saying you'll get more power, but AV fuel because of it's ultra refined nature does not break down as quickly as pump gas.
  8. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    Be interesting for somebody to explain to me what "additive package" can raise octane rating. That takes place in the alkylation and iso units at the refinery. You can't make wine from water unless your initials are JC.
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  9. Pallet Pete

    Pallet Pete Guest

  10. TMonter

    TMonter Minister of Fire

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  11. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    And not one refiner on the planet uses them. Their "additive packages" are detergents for fuel system cleaning and to prevent coke build up. Lead is introduced in the refining process. Not as a additive.
  12. TMonter

    TMonter Minister of Fire

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    Sort of splitting hairs aren't you? Perhaps not the best choice of words but with several of the anti-knock additives used they are blended in after the refining process. I won't claim to know much about the cracking process as I do about the heat generation process side of the refineries I've worked on.
  13. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    And those are alkylate and isobutane. The gas comes out of the refinery at the best octane it is ever gonna be. Additive packages are added at the loading rack locally before delivery to the station since different brands come out of the same tanks at the terminal. The brand specific additives are dumped in just prior to delivery.
  14. jharkin

    jharkin Minister of Fire

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    We just had the avgas discussion in a saw thread recentlly. Other than being ethanol free and better QC avgas has no magic properties... Other than draining you wallet fast. The lead will foul plugs.... And you are poisoning yourself.

    100LL has something like 10x the lead mogas as had before it was banned. Not good.

    ---
    Edit: I looked it up. Before the final ban in the 90s, leaded auto gas contained 0.1gram/gallon lead. 100LL contains 1-2 grams/gallon.

    Also was surprised to learn that only 30% of the general aviation fleet still runs 100LL exclusively, and plans are in place to phase it out completely before 2023.
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  15. velvetfoot

    velvetfoot Minister of Fire

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    I found it interesting that the engine on the new Ariens snowblower I got at the end of the winter has a Briggs engine. I hope it lasts as long as the Tecumseh Sno King on the old one.
  16. fbelec

    fbelec Minister of Fire

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    tecumseh engines always worked well for me i like them better than bs engines. what happened to tecumseh company?
  17. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    I have a cast iron Tecumseh one lunger on an old 4,800 watt generator that just refuses to die. Thing weighs a gazillion pounds. I have a newer three horse on the shelf that I have been planning to use for something for 28 years.

    "On February 10, 2009, Platinum Equity LLC announced that Tecumseh Power Company had sold certain assets of its engine business to Certified Parts Corporation. This included the sale of existing and unfinished engine parts inventory, tools to make finished product and certain intellectual property assets. Certified Parts Corporation also assumed responsibility for warranty of previous engine sales."

  18. blades

    blades Minister of Fire

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    Tecumseh belly up.
  19. nate379

    nate379 Guest

    Believe whatever you'd like, I'm not going to continue to argue. The info I posted is correct info. I did go to school for this stuff... did you?

  20. nate379

    nate379 Guest

    Dunno but did they ever built an engine that was closed to balanced?! My Dad had one on a wood splitter and the thing would walk around a bit from it shaking so much! Been the case for every one I've used!

  21. TMonter

    TMonter Minister of Fire

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    I hold a masters in combustion engineering, so yes.
  22. Danno77

    Danno77 Minister of Fire

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    I haven't had the best luck with my briggs engines, but I didn't take good care of those things because they were cheaper. Things that I own with Kohler or Kawasaki engines were freaking expensive, so they receive my best attention. Kinda a catch 22...
  23. MasterMech

    MasterMech Guest

    I'm going to print myself out one of those, it's a phony sure, but it just sounds so cool. :p
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  24. jharkin

    jharkin Minister of Fire

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    Typical Lycoming and Continental flat 4s and 6s you find in your average Cessna or Piper run closer to the low 2000s at cruise. A big O-540/580 used in competition aerobatic aircraft might hit 3000, but not for long periods.

    Lead does provide lubrication but it was actually originally put into avgas as an octane booster. It was the only way to hit the very high octanes (100/130 and 115/145) that the big WWII aero engines needed for high altitude supercharged operations.
  25. Danno77

    Danno77 Minister of Fire

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    I hold an associates degree in Combustion Theory.
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