2 or 4 cycle trimmer

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

  1. birddseedd

    birddseedd LawnSite Silver Member
    Posts: 2,114

    so what you are saying is the government is wanting me to buy a new muffler every 50 hours?
     
  2. GrassGuerilla

    GrassGuerilla LawnSite Bronze Member
    Posts: 1,437

    Your mostly right. But the numbers appear to be just arbitrary. Why would you need to replace a non-cat muffler? The non cat muffler should be fine on older models with an adjustable carb. Just don't put a cat muff on one that came without. That may well cause a meltdown.
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  3. JCLawn and more

    JCLawn and more LawnSite Fanatic
    from MI
    Posts: 5,206

    I just read the first 2 pages and everyone who mentioned 4 strokes were talking about the 4 stroke mix engines. Its still a mix engine. You would need to buy a honda, dolmar, or I think kawi to get a true 4 stroke. I have a domar with a true 4 stroke engine with oil seperate from the gas, not mixed. I have at least 700 hrs on it and 0 issues. The only thing is I need to run fuel cleaner in the gas or it has an issue with carbon build up because I run it with the guard off and longer string. I expect to have it for a good 2000-3000 hrs.
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  4. Patriot Services

    Patriot Services LawnSite Fanatic
    Posts: 13,255

    An engines stroke design is not determined by the fuel it burns. A 4 stroke engine burning mix is still 4 strokes.
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  5. JCLawn and more

    JCLawn and more LawnSite Fanatic
    from MI
    Posts: 5,206

    No but it determines its durability and power. Engine oil will always lubricate an engine better than a mix.
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  6. Patriot Services

    Patriot Services LawnSite Fanatic
    Posts: 13,255

    Do you by chance have some analytic proof of this?
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  7. GrassGuerilla

    GrassGuerilla LawnSite Bronze Member
    Posts: 1,437

    I'm willing to concede that there are a couple of decent true 4-cycles, the 4-mix models are improving. Anybody that's been around a while knows full well 2-stroke is the proven technology for hp / pound. The current climate of the EPA killing the 2-cycle is clear. Have we reached the pivot point where the 4-cycle offering are better than the choked 2-stokes? Close, but not quite. If the fs250 is being phased out as I recently heard. The day may be soon.

    Since Husky bought Redmax, we haven't seen much new stuff from Redmax. Interestingly, their strato technology (on license from Electrolux) has kept most of the 2-stroke manufacturers in the game. Even Stihl is using it in their remaining 2-strokes.

    Is Echo going to be the last 2-stroke non-strato?
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  8. JCLawn and more

    JCLawn and more LawnSite Fanatic
    from MI
    Posts: 5,206

    Do I need to? If gas mix was better you would be filling your crank case with gasoline and 2 stroke mix in your car if it lubricated better and that's what your doing in your hand held trimmers. Your using gas oil mix to lubricate the crank shaft piston, and valves. Also if it was better you would be seeing 2 stokes lasting 3000+ hrs on a regular bases. As far as power goes a dolmar 32.6 cc 2 stroke is 1.3 hp and a 33.5 cc 4 stroke is 1.4 hp. And a 4 stroke will have more torque. Same hp with a lower rpm equals more torque. Also a sthil fs 110 which is 31.4 cc is 1.4 hp. The 4 stroke dolmar is 2lbs heaver than the fs 110 but is only 0.4 lbs heavier than the dolmar 2 stroke. So for less than a half pound your gaining torque, fuel economy, durability, and ease of starting. For 2 years my trimmer has started first or second pull even after sitting all winter.
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  9. birddseedd

    birddseedd LawnSite Silver Member
    Posts: 2,114

    so. i figured out how a 2 cycle actually works. it would seem to me that a 4 cycle would last longer as the parts are better lubed. now. building one that is small enough for cheap and light effectively is another story.

    now, couldn't they make the engine run upside down if they closed off the oil ports and had a separate drain for the oil for the cam?

    what i want to know is can i build a trimmer out of this engine http://www.youtube.com/watch?v=3YfTtGCsiD8
     
  10. JCLawn and more

    JCLawn and more LawnSite Fanatic
    from MI
    Posts: 5,206

    No a reqular 4 stoke engine won't work upside down. My engine has oil injection to make it work in any direction. My trimmer was around $350.
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