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Redmax 7001 Blower Vapor Lock?

Discussion in 'Mechanic and Repair' started by mcambrose, Aug 8, 2008.

  1. mcambrose

    mcambrose LawnSite Senior Member
    Messages: 518

    I have a Redmax blower that runs great except when it sits out in the sun. It will generally start easily, but when I try to give it throttle, it just won't take the fuel. It spits and sputters and dies. If you can keep it running long enough to get it cooled off, it will run fine. (I think it is the carb that needs cooling) It is not a problem with exhaust or the coil. The exhaust is clean and the coil is new. All coil problems I have ever had would stop the unit while it was running and the coil got hot. The problem never shows up while the engine is running. It only occurs after the engine is of and sitting in the sun. I have tried opening the gas tank vent to make sure there was not a stopped up vent, but that doesn't make a change. The factory tech said there might be a stopped up vent for the carb. I haven't been able to find this vent. Any suggestions are appreciated. THanks.
  2. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293



    For the past few years, I have had “vapor lock” conditions on some of my trimmer motors and chainsaws. I am using all Echo units. After normal use, (and especially on a hot day) the motor, after sitting a few minutes, will fire and die. If I place the choke at ½ closed, it may run poorly for a little before dying. All this time, the motor is running in a lean condition, bogging down when the throttle is pressed.

    I was told that fuels were blended by the seasons now. In the Winter the fuel puts off a lot of fumes and in the Summer there were less fumes (these fumes being called “light fractions”).

    The solution was to leave the gas cap off overnight and allow the fuel mix to evaporate.

    I am now buying premium fuel, allowing it to vent at least overnight, and mixing my 2 cycle mix at 32-1 rather than 50-1.

    All seems to help but on a hot day in the winter at Alpine Texas area (5000’ elevation) I still have some problems. It is not fun when I am high in a tree with a saw that does not want to run.

    Anyone else have similar problems.


    ******** post 2 *******

    I go to the limits of my knowledge much too often. Thanks for the post.

    The problem on my equipment is similar but different. After running the 2 cycle motor hard, then immediately putting fuel in it, starting, then the motor will be most difficult to run. The motor is running lean. By forcing it to run by moving the choke in and out and, at the same time, moving the throttle much, the condition smoothes and the unit runs fine. This takes an honest 2 minutes (sounds short on paper, but is “a pain” on a job site).

    Granted some of my echos have 1000hrs+, but some are new. The same thing happens on old and new.

    The hotter the day and the harder I run the saw or trimmer motor (on extension saws), the more common the problem. The larger the motor, the less common the problem (and easier to solve). Seldom does it happen on my CS9000, but it occurs consistently on my 24cc motors on my extension saws. Also common on the 30cc an 34cc saw motors.

    Thanks again and still hoping someone out there has a solution.

  3. mcambrose

    mcambrose LawnSite Senior Member
    Messages: 518

    I have tried solving my problem by pouring cold water over the carb. I have just tried this a couple of times and it did seem to work. I have thought about putting a wet towel over the blower when I stop to work.
  4. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293


    Something that simple might work.

  5. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Messages: 1,784

    It seems like all the fuel systems issues have been covered in this thread and the one Echoman started a few days ago.

    That brings me to this suggestion, a few years back I had a Stihl 024 come in that had the same problem, hard starting when hot. After a battle of wits with the chain saw, what I came up with is, changing the Champion plug to a Bocsh of the same heat range. Changing the plug worked, no problems since.
    For what ever reason, Champion and NGK would not work in the 024.
  6. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293


    Changing a plug is easy and cheap. I have 4 units I use daily so why not change 2 to test.

    Thanks again
  7. jkason

    jkason LawnSite Senior Member
    Messages: 546

    Echoman, your problem might be elevation, too.
    I'll pray that you have adjustable carbs on the things.
  8. echoman8

    echoman8 LawnSite Senior Member
    Messages: 293

    Yep, work ranges from 4500 to 6000 in the low west Texas mountains and then I drop to 3000 here around Odessa.
  9. 2k1yzfr1

    2k1yzfr1 LawnSite Senior Member
    Messages: 539

    Mcambrose......what octane fuel are you running and what brand are you buying?
  10. mcambrose

    mcambrose LawnSite Senior Member
    Messages: 518

    87 octane. It is Kangaroo Brand. Just a low price high volume seller. Note that I don't have the same problem with my Redmax trimmer.

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