A forum for owners of Yamaha TTR250 trail and enduro bikes!

i am buying a new socket set, and would like to know the largest nut that is on a TTR so i can get a set that will service my bike without having to go parts shopping half way through something.

also if the nut is metric or not would be great too.

cheers.

davecambo wrote:

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page 2-14 of the workshop manual has "Cap nut and inner tube - M40" what the????

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That's the cap that screws into the top of the fork leg stanchion. The ones I repaired recently didn't have a nut that size but I know there are two different designs of fork leg. Will try and remember to have a look later.

Brian

The aluminium nuts on the fork tops on my TTR are 30mm - the same size as the nut securing the gearbox sprocket.

Martyn

davecambo wrote:

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page 2-14 of the workshop manual has "Cap nut and inner tube - M40" what the????

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The M tells you that it's metric

The 40 tells you that it's a 40mm diameter thread

So M8 tells us that it's a metric thread 8mm diameter, M14 that it's a metric thread 14mm diamewter.

These sizes don't have much to tell us about a spanner size to be used which is measured across the flats of the screw/nut.

An M8 screw is a thread diameter of 8mm which may have a 10mm hexagon or 12mm hexagon head.

So the M40 is a thread diameter of 40mm but the spanner size is 30mm because the hexagon is a smaller diameter than the thread - as the fork cap nut is.

Q.E.D.

Martyn