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My 21" Proline Knocks?

Discussion in 'Lawn Mowing' started by outrunjason, Sep 29, 2002.

  1. outrunjason

    outrunjason LawnSite Senior Member
    from dallas
    Messages: 719

    I can't figure it out. I have had this mower for 2 years now and it always sounds like it is knocking but I am thinking it is my fuel mixture. I recetently got another used 21 Proline and it had gas already in it and it didn't sound like it was knocking. As soon as I put my mixture of gas in it it started to knock.

    I am using Echo 50:1 mix. Should I switch brands or adjust ratio?

    Thanks, Jason
  2. DLS1

    DLS1 LawnSite Bronze Member
    Messages: 1,619

    I bought the 21" proline 2 cycle beginning of season and it knocked and smoked enough to burn my eyes sometimes.

    I switched oils to John Deere 'Universal ' 2-cycle oil sold at Home Depot - 16 oz. size that makes 6 gallons. Now I have alot less knocking and alot less smoke. Still will get some smoke since you have oil in the gas.

    Just experiment with different oils.
  3. try amsoil 2 cycle oil great stuff
  4. outrunjason

    outrunjason LawnSite Senior Member
    from dallas
    Messages: 719

    Well maybe there is not enough oil in mine cause it never smokes at all. I just switched to that john deere stuff you are talking about but I have a 5 gallon tank. I think I am just going to pour the oil in the 5 gallon and make it a little strong and see what happens.

  5. Keith

    Keith LawnSite Gold Member
    Messages: 3,979

    Jason, does it seem like it's down on power at all? I remember our old Toro 2 cycles would run like crap and knock like hell when they would sheer a flywheel key. It was a pretty regular occurence, at least once a year. Also our last one, back in 95 was a knocker, it just steadily got worse until we quit using it. I believe it had crankshaft related problems.
  6. outrunjason

    outrunjason LawnSite Senior Member
    from dallas
    Messages: 719

    It is somewhat down on power. I have a tachometer on it and it was reading about 3,500 last year. Now it is about 3,000. I also checked what I think is the cotter pin and it looks good to me. I adjusted the spring to get it to run a little faster.

  7. sirsweatsalot

    sirsweatsalot LawnSite Senior Member
    from MN
    Messages: 296


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