I retorqued all the head and cylinder nuts on my 1972 750 commando today to hopefully eliminate an oil leak problem (separate thread…I think I’ve found the problem) but I was unable to find any tool that would fit onto the rear cylinder head nut. I tried a 1/4W open spanner but I could not turn it to engage the nut before the spanner fouled the fins. I tried a 1/4W ring spanner but that would not fit either, I even filed off some of the outer ring (7/8” across)! I’m wondering whether an oversize nut was fitted in the past but goodness knows how. Anyway, please can someone look at the photos and let me know whether this looks normal, and I simply need to buy a very thin ring spanner of a very thin open spanner? Thanks
It is a tight fit. Some…
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Thanks Stan. I’ve got a nice…
Thanks Stan. I’ve got a nice 1/4W cranked ring but too much offset, it hits the fin below the nut. I’m trawling eBay at the moment otherwise it’s £25 for the nice Andover Norton cranked one
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Britool spanner I nicked…
Britool spanner I nicked from my father half a century ago. Yes, the handle does touch the cylinder fin when putting it over the nut but it clears when in position.
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My dads stuff….
…got me by then and now. Most came from George Stephenson era!
One little tip is the first 1/8 of the spanner does not engage with the nut so flush it off ( it’s only there to slip onto a nut when you are out of sync with the flats). This reduces the issue of interference with fins when positioning it. It also stands out in your tool collection as a special and should be identified as so. I have mods to a few bits and pieces , if I don’t label them I forget what they are for.
Jon
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I got a ring spanner..
.. from a car boot sale / autojumble and chopped it in half so it didn't collide with carbs etc when torquing down after rebuilding. Even though I no longer have a Commando it's still useful for awkward nuts.
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It is a tight fit. Some barrels are more awkward than others. Use a 12-point ring spanner with the outside ground down if necessary. It's a 5/16" BSF (1/4" Whitworth) nut, same size as the heads for the 4 bolts next to the spark plugs. Favourite is a 1/4"BSF & 5/16" BSF double ended cranked ring spanner which you can use on the nuts at the front too.