2 or 4 cycle trimmer

Discussion in 'Mechanic and Repair' started by birddseedd, Mar 15, 2013.

  1. newz7151

    newz7151 LawnSite Silver Member
    from Tejas
    Posts: 2,419

    Echo has some strato charged engines.

    And you don't put a non-cat muffler on an Echo engine designed for a cat muffler because #1 you've voided your emissions warranty and if they ever start doing random checks in places for something like that...... And the engines are tuned at the factory to run with a certain amount of back pressure which is provided with the cat muffler, as far as your "adjustable carburetor" to adjust around that, reference my previous sentence about EPA and random checks....
     
  2. newz7151

    newz7151 LawnSite Silver Member
    from Tejas
    Posts: 2,419

    Also, for those of you saying "Buy a Kawasaki handheld, Kawasaki will no longer be a player in the hand held market when the Kawasaki hand held equipment is discontinued in December 2013.
     
  3. birddseedd

    birddseedd LawnSite Silver Member
    Posts: 2,114

    so brings up my previous question. if after 50 hours you are not adhering to the spa regs..... buy a new one every 50/300 hours?
     
  4. GrassGuerilla

    GrassGuerilla LawnSite Bronze Member
    Posts: 1,437

    Wow. Warranty schmaranty. Random EPA string trimmer inspections huh? Too much. Congrats EPA, ya got me. Polluter of the year. I've fattened up my trimmer a little. For goodness sake, don't check my chainsaw.
    Posted via Mobile Device

    The extra performance from yanking a cat mufflers guts out, and opening up the flow, must be tuned for by fattening up the carb, or changing out the jets. Not done much around here. But it's about like going up an engine size. IE going from 23-25cc performance level. Guess they'll just plain lock me up if I port my trimmer?
     
    Last edited: Mar 18, 2013
  5. jkilov

    jkilov LawnSite Bronze Member
    from MS
    Posts: 1,415

    AN EPA rating of 50 hrs does not mean the engine lasts only 50 hrs or that emission components have to changed at that time, etc.

    This is more of a manufacturer thing than a user thing. It means the manufacturer (i.e. Stihl, Echo...) has to build the engine in such a way it's emissions will be within spec for a compliance period based on it's field of use:

    Moderate: 50 hrs (homeowner equipment)
    Intermediate: 125 hrs (semi-commercial)
    Extended :laugh: : 300 hrs (commercial - that's us)

    Not sure how EPA came up with these numbers but could be that it was adapted to the current state of junk equipment available at box-stores which would have difficulty surviving come of these tests. Or could be that EPA people work only 2 hours a day.

    Anyway, I kinda got used to 4-strokes and they have some benefits. The exhaust ports aren't clogged up, the noise is far nicer, they don't get as hot as catalytic 2-stokes or act as anemic on start-up. What's more mine (have both 4-mix and C4) seem to keep their compression very well (no ring wear on ports), but yeah I can image them being less reliable.

    Either way the old 2-strokes are gone. For every 3 tanks of fuel you might as just spilled one one the pavement.
     
  6. GrassGuerilla

    GrassGuerilla LawnSite Bronze Member
    Posts: 1,437

    Hmmm, then there must b some supernatural explanation for 10 and 12 year old Echo's with thousands of hours. Or 5-7 year old Redmax's with easily 2000+ hours. Ill grant that the Echo isn't the most fuel efficient. I'd compare Redmax strato to any 4-cycle in terms of efficiency.

    Not mixing gas is nice and all. But unless your getting rid of the mixed gas machines, what's the point? Having some handhelds run on mix, and others run straight gas is asking for trouble. People make mistakes. Don't set them up to fail.

    I will let you fellas run R&D for the big boys on the four strokes. When I join the ranks, it'll be because the remaining options suck worse.
    Posted via Mobile Device
     
  7. birddseedd

    birddseedd LawnSite Silver Member
    Posts: 2,114

    but if the engine no longer work to epa regulations are we not required by law to get back into spechs?
     
  8. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 12,961

    What does this mean......old ones gone guess I got the new ones this year?
     
  9. BigFish

    BigFish LawnSite Silver Member
    Posts: 2,918

    I ain't read but the OP (#1). Skimmed thru the rest of the babblin'.
    That said, I would buy a TWO CYCLE straight shaft, solid drive shaft unit, PERIOD!!!
    The rest is junk, in my not so humble opinion.
     
  10. jkilov

    jkilov LawnSite Bronze Member
    from MS
    Posts: 1,415

    By "old-ones" I meant pre-EPA 2-strokes. Pure Schnurle ported would be more accurate.

    A 2-stroke engine is a design flaw in itself. Both intake and exhaust ports are open at the same time allowing fuel to short-cut directly to the muffler. The old 2-stroke could hence loose about 1/3 of it's fuel directly to the exhaust. This resulted in fuel consumption figures over 600 g/hphr and hydrocarbon emissions of 200 g/hphr, simple math.

    However this fuel wasn't completely lost, since it evaporated it cooled the engine directly proportional to the heat being generated. Old 2-strokes were easy to start, responsive and fast to warm up, yet difficult to overheat and with great torque.

    On the other hand all modern 2-strokes (2-mix, tornado, stato) and other fancy names use a lean-mix carburetor with various tricks (air plug, port block or resonator) to reduce the short-cutting effect and/or a catalytic muffler to burn off the rest.

    Unfortunately, lean setting makes them "cold-blooded": hard to start when cold, anemic performance on warm-up yet very hot running afterwards. Those with catalytic mufflers also suffer from heat soak when turned off making them stubborn to restart immediately after.

    Hence my preference the 4-stroke.
     

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