Honda Izy Mower - How to Adjust Carb?

Discussion in 'In the Garden' started by RBZ5416, 25 Mar 2012.

  1. RBZ5416

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    Took a brave pill & pulled the carb apart. There was some muck in the bowl so I cleaned it & the jet as best I could. Now it starts but will only run relatively smoothly with the choke on. Back it off & it hunts/pulses so I guess I need to adjust the mixture but can't find any info...
     
  2. Burnerman

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    There are 3 jets on these engines.....with the float bowl off, the main jet can be unscrewed from the central hole. On top of this jet - occasionally its the same brass bit - iis the emulsion tube, with holes drilled across its length.
    The pilot jet is not actually removable, its a drilling in the carb body. You'll find the 'tamperproof' adjusting screw on the carb top - this only allows you to adjust the pilot mixture 1/2 a turn. I usually break the plastic bit away, and unscrew the pilot screw beneath, counting how many turns it is from fully in.
    Remove the white plastic float by sliding its pin out - with it will come the needle jet that allows fuel into the carb. Its vital that the needles seat is clean.
    After that, its a good blast throughout with compressed air and aerosol carb cleaner....please, no cloth or kitchen paper!
    Anyhow.....the pilot jet is only used on tickover, the main jet is for full speed running, and the emulsion tube for the transition between the two, so the fault is likely to lie within the main jet, the emulsion tube or the float needle valve.
    John :)
     
  3. RBZ5416

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    Thanks, that's much appreciated. :D

    I pushed a small needle through the main jet & that seemed clear. But I guess miniscule amounts of dirt could cause a problem given how small the jet is.

    Should the emulsion jet just fall out of the body once the main jet is removed?

    I don't have access to a compressor, is an aerosol can up to the job?

    Is Redex any good for these carbs?
     
  4. Burnerman

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    Depending on the age and engine fitted to your Izy, the brass central bolt that holds the float chamber on is the main jet - it has one hole drilled down its length, and another drilled across it to connect. Fuel from the float chamber passes through this jet on the way up to the emulsion tube.
    Peering up the emulsion tube hole, if you can see a screwdriver slot then undo it, and the tube slides out.
    Although compressed air is obviously the best, an aerosol carb cleaner will have to do - it should work.
    Take note that the float chamber actually has a step on it (usually) that the float drops into, so its worth marking its position! Don't lose the rubber 'O' ring that seals the bowl to the carb body.
    The other screw in the float bowl is there to allow you to drain the float chamber if you need to - the slightest ingress of water at any time causes rusting in the float bowl.
    Redex (upper cylinder lubricant) isn't needed in any way.....unless you're talking about a carb cleaner made by Redex!
    At the risk of sounding like a true anorak, you have one of the best machines around.
    John :)
     
  5. RBZ5416

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    It's a 2003 HRG415C2 (GCV135?).

    I guess water must have got in a some point as there was corrosion at the bottom of the bowl. No idea how though.

    The Redex I was thinking of was this as it's claimed to help keep carb jets clean.
     
  6. Burnerman

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    Feel free to use this if you want, but these 'canned mechanics' are all over the place, and I seriously doubt some of their claims.... :p
    Many problems I attend to are caused by owners using rusting or contaminated fuel cans, and one of the things I do when I have an Izy in for repair is to pump the fuel out of the tank and make sure that the filter (just inside the tank at the fuel outlet, non removable) is clean.
    The stuff that Redex produce is claimed to remove resin or varnish deposits left by fuel - it may well work but you won't notice any difference and it certainly has no effect on dirt or moisture in the fuel.
    John :)
     
  7. RBZ5416

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    Thanks again, your input is much appreciated.

    After all my failed Googling efforts previously I've just found this. May help others.

    Edit
    As may this & this. The key seems to be to research which engine you have (listed in the specs of the user guide) & then search on that rather than the mower.
     

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