New Syphon

[wobs]

I have fitted a new syphon to our toilet, and we've had a number of issues with it regarding the flush. I originally had a 9" syphon, and after struggling to get it to work, tried an 8".

This is slightly better, but if you flush it at just the wrong speed (ie. how my daughter uses it), it won't flush. I've tried changing the diaphram, and no joy.

This is upsetting my daughter, as she's only 5.

The toilet downstairs works fine, and its the same make of syphon, and also about 8".

Is it just luck between different syphons, or is there some otyher issue, such as the angle of the lever?

 

[Burnerman]

The diaphragm needs to be fully pulled up if at all possible, and keep the water level in the cistern as high as possible too - just under the overflow.
John

 

[wobs]

Thank you for the reply.

I've set the lever so it can't rotate over, so its stopped by the diaphram, so I assume its going as high as it will go.

And I've set the water level to just below the over flow.

Its a Macdee Metro oblong adjustable flush syphon.