Recent content by brianmk

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    Mountfield Emblem carb diaphragm and intake tube/manifold

    The cork gasket has fixed the fuel leak from between the carb and tank but the poor starting problem remains. After running out of ideas on the fuel system, I spent some more time checking the ignition. I removed the spark plug, connected the plug body to the engine casing and turned the engine...
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    There is still a fuel leak between the bottom of the carb and the fuel tank - even with the new diaphragm. I decided to take it apart yet again and re-check the flatness. As far as I can tell, the base of the carb appears to be flat. However I think the top of the fuel tank where the carb fits...
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    Today I tried to start the mower once again. It still takes over a dozen pulls on the cord to get the damn thing to start. Nothing I have tried has made any difference. I have received no suggestions or advice from this forum. I think it's time to give up and buy a new cordless electric mower.
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    I began to wonder if the starting problem might be connected with the ignition system rather than the fuel system. Perhaps the spark is not strong enough to allow easy starting even though the engine runs ok onece it gets going. So today I checked the coil, HT lead and spark plug resistance...
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    The service manual is one of the worst I have ever encountered! Rather than have separate sections for each of the many variants, it jumps back and forth between variants in different paragraphs leaving the reader confused as to which paragraphs are relevant for a particular model. The manual...
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    I was already aware that the diaphragm and spring shoul be preloaded using a 3/8" bolt or drill shaft to hold the choke butterfly open while tightening the carb fixing bolts. That information is provided on the card that comes with the replacement. I assume you mean flatness rather than...
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    I should have added that I had already checked that the choke butterfly was working as expected (i.e. closed on start up) before embarking on the diaphragm change. Although the diaphragm was old, there were no obvious holes or tears. Once the engine had started it ran ok. It often took a dozen...
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    Mountfield Emblem carb diaphragm and intake tube/manifold

    My old 15" Mountfield Emblem has been difficult to start lately. It has a Briggs & Stratton vacu-jet carb with a choke. The carb fixes to the fuel tank with 5 fixing screws. I decided to try changing the diaphragm. I had a spare diaphragm I bought via eBay in 2019. The box was stamped 390834...
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