Replacing toilet syphon - does size really matter?

[kepha]

Hello all,

The linking rod connecting the diaphragm of my syphon has sheared at the base. I'll need a new syphon but no-one seems to have the right size syphon and no chance of any deliveries/post at the moment due to heavy snow. I'm slightly confused about what size syphon I'll need and whether I could get away with a smaller one than the existing part - it's a single toilet house and I'm not sure I can wait until the snow melts!

Here's the details:
Derwent MacDee Metro toilet syphon (http://www.bes.co.uk/products/119a.asp#11666). Thank goodness it's a 2 part syphon!

Here's some pictures (you can see where the rod has sheared):

Distance from bottom of red cap to bottom of syphon: 11 inches. Syphon itself is marked with '1 litre'.

And here's the cistern (water-level is 8 inches deep)

Any tips about what to do next?

 

[PEDANTICVINDICTIVEMAN]

9" Dudley Turbo syphon should fit, but means disconnecting and removing cistern to do the job, unless your really good at diy plumbing, I would get someone in as it can be a sod of a job if screws bolts rusted, I would also fit a new filling valve at the same time if I was doing it, as the arms tend to fall off at the hinge point on the one shown.

 

[seco services]

you'll probably get away with a 9 if the water level is the correct height.

 

[kepha]

Thanks for the advice, much appreciated.

Don't really fancy taking the cistern off myself and getting a plumber at this time might be difficult given that they're probably inundated what with this weather.

Water level comes up to marked line in cistern so I'm guessing it's correct. Should I just go ahead and get a 9 inch and hope it works? I can get hold of a 9" replacement Derwent metro - plumb center said they've got it in stock.