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tsunami_gw

Honda lawn mower carburetor leaks badly

tsunami
12 years ago

I have a Honda HRX217KHMA that wouldn't start. I'm almost certain that it needed a carb cleaning from sitting too long over the winter months.

So I took the Keihn carburetor apart and cleaned all orifices with W-D and blew them out with compressed air. I also removed the jet and did the same.

I put everything back together, turned on the gas valve and found a lot of gas leaking. I couldn't see where it was coming from because the air filter assembly blocks the view of the carburetor. But it felt like it was leaking from the where the bowl meets the carb body. I figure it must be the gasket since I reused the same one although it looked fine.

I took it apart again and made sure there was no gas in the float and that it moved freely, and changed the bowl gaskets. I put everything back together, turned on the gas valve only to find that again, it leaked badly. But I can't see where it's coming from because of the air filter assembly.

I doubt it's leaking from the gaskets since they're new I'd think that any leak would be slow. It's as if the float is stuck and the carb is overflowing, but it looked fine before I put it back together.

A friend tells me that maybe the o-ring where the needle seats fell out during dis-assembly. I can't find a parts diagram for that model, but I checked a parts diagram of a Keihn carb from a similar model HRX217HXA and don't see any o-ring or seat where the needle goes.

Any help would be appreciated.

Comments (4)

  • tomplum
    12 years ago

    No o-ring to worry about. A new carb and gaskets to fix whats broke will set you back maybe $25 though.As you probably know, the fuel tank comes off easily so you can flush out the tank and lines.

  • tsunami
    Original Author
    12 years ago

    Thanks for clearing that up. It didn't look like an o-ring belonged in there.

    And no, I didn't know the tank comes off easily! I haven't considered removing the tank yet. I put some Seafoam in it when it wouldn't start. But I guess it won't work unless the engine is running.

    Also, on this carburetor, it doesn't look like the seat is removable.

    I'm going to try and run it tomorrow with the petcock closed. Maybe the float will drop and dislodge itself.

    It's good to know that if it keeps leaking, the carb seem's rather inexpensive.

    Thanks!

  • tomplum
    12 years ago

    I always remove the tank (via the 3 recoil nuts) and give it a rinse, plus wrap a shop towel around the line and blow thru it with mouth pressure (with the bowl off). It helps get whatever is laying in the line and valve out of the system. I believe you are correct that the seat is non serviceable.

  • tsunami
    Original Author
    12 years ago

    I couldn't get it to start, so I made sure that it had spark, and it did. So I took off the air filter and linkages, but left the fuel hose on to try and track down that leak.

    I'm almost certain that it's coming from what I think is the main jet in the center of the throat of the carburetor which leads me to believe that the float must be holding the needle open. Or maybe the needle is not sitting right in the float.

    So I disconnected the fuel hose, drained the fuel out of the carb, and tried to listen if I could hear the float move as I moved the carb around. I could hear it moving.

    I put everything back together and it stopped leaking. And finally, got it to start. So I mowed the overgrown lawn while I could. The idle would bounce up and down, but under load it would run smoothly.

    When I was done, I checked for leaks and noticed it was leaking again, apparently while I was mowing the lawn. I'm about to throw in the towel on this one and just buy a new carb.

    But first, I was wondering if there are any carburetor adjustments I could make that might stop the leak? When I screwed in the main jet, I turned it in all the way. I'm wondering, should I have set it at say, 2 and 1/2 turns out? Or maybe some adjustments on the screws on top of the carb body? I haven't even touched those.