Redmax EBZ8001 issue

Discussion in 'Mechanic and Repair' started by BruceSr, Aug 29, 2018.

  1. BruceSr

    BruceSr LawnSite Member
    Messages: 7

    I have had my Redmax EBZ8001 for over 10 years now, LOVE it!

    This year is has started a new problem. Starts up fine, but when for about the 15 to 20 minutes it will not get to full speed. It will only get up to about half speed, but then all of a sudden it starts working fine, almost like it needs to warm up.

    Tried a replacement carb, no change so I put the original one back on. New spark plug, no change.

    The only thing I have noticed is that there seems to be some oil build up at the bottom of the intake (area after I take the round intake tube from the air cleaner to carb off). Used to run better when I cleaned that with carb cleaner, but now that is no help.

    Per the user manual, my gas mix is 2.6 oz to 1, using premium gas for the mix.

    Had the pistons replaced about 5 years ago because I was using regular gas.

    Any ideas on what the issue can be?
     
  2. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 15,198

    Be sure exhaust ports are clean......fuel filter new...any leaks behind the recoil or flywheel. Crank seals could be worn out on 10 year unit. If carb has adjustment open up high side a little. Don't assume new carb would be adjusted correct for old machine.
     
    hort101, sjessen and Breezmeister like this.
  3. BruceSr

    BruceSr LawnSite Member
    Messages: 7

    No adjustments on the carb that I see other than the idle.

    All of the other suggestions seem like they would be all the time, not just when it is warming up. The other aspect that puzzles me is that this should be warmed up after 5 minutes or so, but it only gets to full speed after 15 to 20 minutes of running?
     
  4. Breezmeister

    Breezmeister LawnSite Silver Member
    Male, from South Jersey
    Messages: 2,141


    At this point I would do a compression test.

    When you replaced the piston, did you replace the cylinder too ?

    Could be a bad cylinder gasket, once the cylinder heats up and expands, it seals up.....And or the fasteners have worked their way loose, just a little.....
    .
     
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  5. BruceSr

    BruceSr LawnSite Member
    Messages: 7


    Good point! Any idea of what the compression should be?
     
  6. Breezmeister

    Breezmeister LawnSite Silver Member
    Male, from South Jersey
    Messages: 2,141

    100 psi or better
     
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  7. BruceSr

    BruceSr LawnSite Member
    Messages: 7

    Good call! Tested it and basically very little compression, so I assume that replacing the piston and rings will do the trick?
     
  8. Walker56

    Walker56 LawnSite Silver Member
    Messages: 2,019

    Not until you verify, as Breezmeister suggested, that your cylinder gasket is good or not. I would not change the piston/rings without replacing the cylinder as well. There are plenty of kits available on Ebay
    https://www.ebay.com/itm/RedMax-EBZ...7xac1uv:sc:ShippingMethodStandard!10983!US!-1
     
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  9. Breezmeister

    Breezmeister LawnSite Silver Member
    Male, from South Jersey
    Messages: 2,141


    I always replace the piston and rings with a new cylinder.
     
    Walker56 and hort101 like this.
  10. BruceSr

    BruceSr LawnSite Member
    Messages: 7

    So a few things did not make sense so I did a little more thinking! I know SCARY!

    The compression was good, took the carb off AGAIN, cleaned it with carb cleaner, put it back on, still no change.

    Chatting with a buddy of mine and he said he uses Sea Foam. I have a bottle and put about an ounce in the tank, within a few minutes of starting it up, is now running at full speed. Let it sit for a few hours tried it again, almost full speed right off the bat after starting it. I put moire Sea Foam in the tank and will use it regularly to keep the carb clean!

    I am now a big fan of Sea Foam!
     

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