Heat, humidity, and 4 mix

Discussion in 'Lawn Mowing Equipment' started by JTLarson, Aug 22, 2014.

  1. JTLarson

    JTLarson LawnSite Senior Member
    Male, from Shenandoah, IA
    Messages: 274

    My stihl KM130's flood out constantly with the heat and humidity we are having. Is a 2 stroke any better for these weather conditions? Or another brand? Can't afford the downtime to have at a mechanic and they have the new nonadjustable carbs without the special tool that you can't get.
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  2. QLM

    QLM LawnSite Senior Member
    Messages: 255

    Man I am in a ton more heat and humidity in Louisiana. How old is the unit? Have you adjusted the valves? Have you run seafoam thru it or anything? Your problem hard starting is almost always valves. Check you air filter sometimes they get full of fuel and can't draw air thru them. Keep a spare with you. If that is the problem swap it and work.
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  3. kawakx125

    kawakx125 LawnSite Bronze Member
    Messages: 1,130

    vapor lock, not much you can really do about it. pressure builds up in the tank with these EPA caps they require now and stuff gets harder to start in this heat
  4. Ridin' Green

    Ridin' Green LawnSite Fanatic
    Male, from Michigan
    Messages: 17,828

    could be a lot of things going on here, but the first thing I'd do is adjust the valves, because hard starting is a good indicator it is time. The new valve cover gasket and the special feeler gauge are only about $1.50 each at the dealer, and it takes about ten minutes to do. My 4-mix equipment has always started great no matter the weather, and we have plenty of humidity here right now.
  5. lawnboy dan

    lawnboy dan LawnSite Gold Member
    Messages: 3,716

    its the heat. yesterday after 99 deg all day . 2 of my weedeaters would not run. one a old redmax and the other a fairly new husky 325. neither of these has ever done this before.
  6. recycledsole

    recycledsole LawnSite Gold Member
    from MD
    Messages: 3,274

    How do you adjust the valves ?
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  7. GoPappy

    GoPappy LawnSite Bronze Member
    Messages: 1,175

    My KM130 only has a few hours on it, but it starts easy and runs great. I'm in the Dallas, Texas area, so we have plenty of heat and humidity here. I ran it today for an hour or so, and had no starting or running problems.

    But, the first thing I had to do was ignore Stihl's starting instructions. If I follow Stihl's instructions to the letter, the thing is almost impossible to start.

    If I start it the same way I've started every trimmer, chainsaw, blower, etc. I've ever used, it starts right up on the 2nd or 3rd pull when cold, and 1st or 2nd pull when hot.
  8. GoPappy

    GoPappy LawnSite Bronze Member
    Messages: 1,175

  9. larryinalabama

    larryinalabama LawnSite Fanatic
    Messages: 19,646

    I have 3 Kombi heads, last week I only had one that ran.

    If you like working on your equiptment Sthil is the only way to go.'

    For me Ill be switching to Shindawia in the coming years.
  10. gebby

    gebby LawnSite Senior Member
    Messages: 712

    I have all Stihl power heads. Here is what I do. If it does not start or if it runs like crap, I look at it and I fix it if I can. If not I take it to the Stihl Repairman. I don't know everything about them. They should. Like most everything else cars, computers, mowers and yes even hand held equipment, I don't have to know how to fix it to use it. I'd rather spend my time making money instead of working on something for hours that cost just 25.00-40.00 to fix. I probably spend on average 35.00 yearly for each item at the shop for the year. I started with Stihl 20 years ago and still use them. Every one starts the same way. Choke, 3 pumps, turn on, pull. If it does not start in 3-6 pulls, go to the next. I try later in the day and it usually starts if not, I check it, and if necessary take to the shop. I run only hi-test gas and Stihls best oil. I may change the plugs yearly at the beginning of the year, even if they still look good. I have found that if it does not start, me or my helper did not try to start in the order above. Leave it sit for 5-10 minutes and try it again. A new guy will often try. If it doesn't start, they did something wrong and out of order. One more reason why they are all the same. Never left to wonder how to start it. I have one unit that is at least 10 years old. It will start within 3 pulls 99 out of 100 times. We still use it every day. So, having said all of that, operator error.

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