Equipment "vaporlocking"

Discussion in 'Mechanic and Repair' started by Jason Rose, May 24, 2005.

  1. Jason Rose

    Jason Rose LawnSite Fanatic
    Messages: 5,858

    Well, I don't mind the heat as much as my mowers, and blower does... If it's above 85 of 90 degrees things are getting hard to start all the time. My 23 hp Kohler will stall and die if I have had it running and shut it off for a few minutes and then re-start it. I'm pretty sure that the heat off the muffler combined with the air temp is just boiling the gas out of the carb.

    My sthil handheald blower drives me nuts though. If it's over about 80 degrees you have to hold the choke lever and move it back and forth from choke to run for about a minute or better to keep it running. If not it just leans out and dies. Again, I think the fuel is evaporating out of the lines or the carb as it sits.

    Today my 9 hp B&S on my troybilt that I had ran 30 minutes earlier would not start for the world, well after about 30 pulls and playing with choke on and off it finally fired. Again, I assume it's the same problem as the others.

    Is there anything to solve this? I use regular unleaded fuel 87 octane. Would a higher grade vaporize as easily as the lower grade? I was under the assumption that the higher grades actually evaporate faster.

    We all are working in the heat, but for some reason I notice it's worse this season already with these problems. Obviously the equipment does eventually run but it's still a little irritating...

    Any obvious fixes out there?
  2. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Are you choking the kohler and troy-built on warm or hot restart ? ,You may be flooding them,Try restarts without choke and see how it goes.
    sounds like the blower could use a carb. adjustment.
  3. Jason Rose

    Jason Rose LawnSite Fanatic
    Messages: 5,858

    Heck no, no choke... Unless I crank it over for a bit and it won't fire and then I add some choke. The kohler will fire and run fine for about 5 seconds then will just stall. Then I HAVE to choke it to get it re-started.

    The Sthil blower USED to run fine till I took it for a tune-up a year ago. Now it runs better at full throttle, dosn't 'clobber' out run rough at full throttle. I guess that's running lean.
  4. Redneckn

    Redneckn LawnSite Senior Member
    Messages: 294

    Don't use any higher octane than regular 87. The higher octanes burn hotter and the engine is not able to cool it effeciently and in the long run will break an engine down.
  5. fixer67

    fixer67 LawnSite Silver Member
    Messages: 2,098

    This may sound odd but try gas from another station. No two stations(brand names like Shell) refine gas the same way. There all do it just a bit differant. Take my '77 Dodge for example, if I get gas at the Texaco station my car runs bad and has no power and the gas hand falls like rock. But I can get gas almost any where else and every thing is just fine. If you are getting gas at the same station all the time try switching stations. If you get gas from all over then I can not help but I will thank on this.
  6. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    Yes I mean there isn't that much can be done, I have that problem with my stuff, too... It usually has to cool off or same thing. Usually if it does not want to start, I let it sit another 5 or 10 minutes in a shady spot and that helps.

    Now I run Amoco Premium and I do not think it helps with this particular problem, but it DOES make everything start easier at ALL times. My first year I ran 87oct and I went through a LOT of starter rope (they just break all the time). After I switched to Super, I hardly replace maybe 1 starter rope a year nowadays, maybe 2 for ALL my equipment. That and the crick-in-the-neck pain from pulling too hard is no longer a problem, I can pull-start the 15hp's with my left hand.

    One other thing, I run synthetic blend oil in everything. This also helps make starting easier AND should you forget to check the oil ... Well I've ran my WB's a quart low before and still ran 15% inclines at full throttle, the only indication was the tick-tick-tick of the valves but then the Kohler likes to do this anyhow, and I've never locked up a motor with synth / blend. But yes, I did lock up a motor once, it was running standard oil.
    Peace out.

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