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Gas mix

Discussion in 'Lawn Mowing' started by walker/redmax, Jul 28, 2006.

  1. walker/redmax

    walker/redmax LawnSite Senior Member
    Messages: 366

    Hey guys! If I tried to mix 40:1 or 32:1 in my redmax trimmers, would I be able to achieve more power. I know you can usually vary the mix in chainsaws. Is the same true for trimmers. By the way, the owners manual says 50:1 which is what I use as usual. The reason I ask is because it seems that these days the way two cycle equipment is built is more in the interest of the environment rather than in the interest of achieving optimum power out of these engines. I just had a thought that more oil might pollute more but could be better for the engine? I'm no small engine mechanic but it was an interesting though.
  2. coyotekid

    coyotekid LawnSite Member
    Messages: 111

    In reality, 50:1 is the correct ratio to run for most purposes. A richer fuel/oil mix definitely won't yield any more power. If anything, it will actually decrease performance slightly but potentially offer better engine lubrication. A two-stroke will yield the highest HP the leaner you go--to a point. Too lean causes excessive heat, and you're headed for a melt-down. Too rich leads to lots of fouled spark plugs and sluggish, poor performance. (This is in regard not only to the fuel/oil mixture ratio, but also the air/fuel ratio. And in this case, "fuel" is the gas/oil mix.)

    Bottom line: Keep it at 50:1 with a quality 2-stroke oil designed for air-cooled two strokes. It's the best compromise, IMHO, between peak performance and longevity.

    If you need more performance, tune the air/fuel ratio via the mixture screws on the carb--most will have two screws: a high end and a low end. Let your spark plug be your guide. A sooty black plug indicates you're running too rich--that is, too much fuel to the given amount of air. A mixture which is too lean will be noted by a whitish discoloring of the plug. You're after a rich golden-brown color.

    If you're in Ft. Collins, I'm gonna say you're about 5,000 ft. above sea level. Chances are your trimmer is jetted for sea-level, so it runs hog-rich up at your altitude since the air is "thinner." We run into the same problem up here in MT.

    Start with a new spark plug and a clean air filter. Adjust the high end screw in about 1/8 turn increments until your reach absolute peak RPM at full throttle. Then I'd richen the mixture (turn screw out) another 1/8 to 1/4 turn depending on the carb to ensure you're running rich enough to let that engine live. Just remember that two-strokes are "fuel-cooled," and you'll be set.

    Sorry for the long post--I hope this helps a guy out!
  3. MOW ED

    MOW ED LawnSite Fanatic
    Messages: 5,028

    Run Amsoil 100:1 synthetic and you will see power like never before without the smoke and soot from conventional oil. I have been running the stuff at this ratio in ALL of my 2 cycle equipment for 10 years now and never had one problem. That equipment includes, Redmax EBZ8000 backpack, Shindiawa backpack, Husky Backpack, String trimmer, Lawn Boy 4.5 hp push mower and Stihl chainsaw. Many many hours on all this stuff on synthetic 100:1 mix. You could fatten it to 80:1 if you wish but I have had nothing but positive with this stuff. Good Luck.
  4. Brendan Smith

    Brendan Smith LawnSite Bronze Member
    Messages: 1,195

    i always mix a little rich. to me, better safe than sorry. i'd rather replace a plug than an engine.
  5. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Messages: 2,613

    I run 50:1 mix in everything including my saws. Havent had a failure yet and spark plugs stay clean and dry. By running a richer mix all you will do is increase carbon buildup and have a poorer running engine over time. Typical american motto here: "If alittle is enough, more must be better!"
  6. Brendan Smith

    Brendan Smith LawnSite Bronze Member
    Messages: 1,195

    i have seen engines fail due to improper lubrication, but never from running rich mixes. you may have to replace a muffler or a spark plug, but not an engine or whole piece of equipment (trimmer, blower, etc.) once a year on my 2 cycle stuff, i remove the plug, spray in top engine cleaner, let sit, then pull cord with plug out to clear it from the combustion chamber. then i lightly oil chamber, reinstall plug, and start. never had a problem yet.
  7. 128Steve

    128Steve LawnSite Member
    Messages: 103

    I vote with Brendan :) In many of my equipment manuals it states to run 25:1 unless in California then run 50:1. So if 50:1 was better, why not run that ratio everywhere?

    Long engine life is not behind the 50:1 ratio. If you go to Kart races (2 strokes), they run ratio's as rich as 16:1. Not one driver runs leaner than 32:1 I am not an expert, but if one goes to BITOG web site there is a great deal of information from very knowledgeable people on this topic.
  8. walker/redmax

    walker/redmax LawnSite Senior Member
    Messages: 366

    I think that would make me a little nervous so I'll go ahead and try it with one of my old trimmers for a while. Do you think that Redmax 2cycle oil would work as well as Amsoil? And thanks to Coyotekid too, I'll give that a shot.:drinkup:
  9. MOW ED

    MOW ED LawnSite Fanatic
    Messages: 5,028

    I think that Redmax has a synthetic oil on the market now although I have not used it. Like I said I have used Amsoil for years and have had ZERO problems. I was amazed the first time I put it in the Lawnboy and it didnt smoke like a chimney. The increase in power is evident however you have to realize taht if you have been running regular petrol 2 cycle oil that your spark arrester screens, mufflers and spark plugs are probably caked with carbon. You may have to clean and replace some parts. You still will get some buildup over time because gasoilne will contribute to carbon buildup but nowhere near the rate at which petrol 2 cycle oil does at those high mixes.
    Clean up the muffler on that trimmer, replace the plug and run a few tanks of Amsoil thru it. BTW I am not a dealer or a paid advertiser for Amsoil. I just use it.
  10. coyotekid

    coyotekid LawnSite Member
    Messages: 111

    Just understand that running Amsoil and petroleum are two completely different scenarios...I would like to try Amsoil 2 stroke oil since I've had good luck with some of their other products.

    The Amsoil is so much more concentrated, which is why it can be run at a 100:1 ratio. I wouldn't recommend EVER running conventional petroleum oil at anything near 100:1 dilution!

    I agree with you guys that running a little rich on the side of caution is not a bad idea, but I'm not so sure it's really needed. I've put a lot of hard hours on two-strokes at a 50:1 dilution with quality petroleum oils with no failures...

    This isn't to say I'm not open to new ideas, though! I learn something new every day and am constantly adjusting and fine-tuning my opinions!

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