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Thin-walled Plug Socket Reccomendations

Discussion in 'Clothing, Gadgets & Equipment' started by Old rider, May 29, 2017.

  1. It's well documented that fitting plugs other then Champion to a Testrastretta motor causes problems with the hex the plug spanner needs to locate on being further down a tapering well.

    I have resorted to filing down my oem plug spanner but this is a less than perfect solution because it has cracked.
    I therefore wish to order a proper thin-walled plug socket but, having been caught out once with one that didn't work, despite the description, can anyone recommend the perfect socket??
    Ideally, it needs to be thin enough to fit down the tapered well and locate on the hex flats, as well as being just the right length to get a ratchet spanner on the end, so you can simply prop the tank up to get the plug out.

    Anybody managed to find the perfect solution??
     
  2. How does the plug hole differ between models ? I have a proprietary socket plug spanner that works with my 748. Need to dig it out to identify the manufacturer but I'm certain it came in a set. Andy
     
  3. The Testastretta engine has a long tapering well and normal plug sockets can't reach the hex flats when the plug is screwed right in. I have a socket that comes as part of the Halfords Professional set but it's not thin enough.
    I don't think this applies to pre Testastretta motors
     
    #3 Old rider, May 29, 2017
    Last edited: May 29, 2017
  4. The O.D. of the Halfords socket it 21.5 mm - it needs to be something like 20mm
     
  5. Okay, I'll have a look in the morning. Andy
     
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  6. I have 2 that fit my 1098. One is very old and I know has no markings on so I cannot tell you anything about it. The second came in the toolkit of my MV 750.
     
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  7. The critical thing is, do they fit NGK plugs or do you have oem Champion??
     
  8. Are you calling me a cheapskate. I have never heard a good word said about Champion plugs only use NGK
     
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  9. Ah but some people insist on oem because Ducati knows best. I think Champion are actually dearer aren't they??
     
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  10. Thanks, CR, what a star you are...
    So this fits and grips and is a convenient length?? Recommended??
     
  11. Works for me. Horizontal is tricky with front wheel in but possible.

    Only issue I had was on 1st use on vertical when I took the socket out it left the rubber insert on the spark plug so I had to dig it out with some long screwdrivers.
     
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  12. FYI IIRC @nelly recommended 0.9mm gap not the OEM 0.6MM.
     
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  13. I use Champion plugs....... In my lawnmower (I think they're the only ones you can get?).


    But NGK in my bikes...
     
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  14. I use a Halfords socket which I turned down on a lathe. Never had any problems and it works on NGK plugs fitted to both my 748's and my 998.

    Filing a socket is pretty unlikely to leave it perfectly round across the whole circumference. If it is lathe turned you can machine it just enough to get it to fit so the minimum amount of material is removed helping to retain wall strength. It also helps to more precisely remove material up the length of the outside wall of the socket, again only going up the socket enough to help it seat correctly on the plug. By using this method you are getting the maximum strength you can expect to achieve and using the inside wall of the cylinder head to help keep the socket in place and to stop it tipping.

    It's probably worth asking an engineering company to do this if you don't have access to machining facilities. I can give you the outside diameter of my socket and how far up the wall I machined it if that helps.

    Apart from buying a really cheap socket that could split or break when undoing the plug any half reasonable socket should do.
     
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