Flush not stopping

[Old Boar2]

I installed a new Dudley 88 adjustable in my elderly cistern. All well and good for two weeks when the syphon did not stop. Changed the flapper (x3), changed the whole thing (x1), changed the side entry float valve, new ball. I have altered the tension on the handle multiple times. I have stuck washers in places and taken the white side plugs out and in again. I have altered the height to every combination. The flush pipe (cistern to loo) was altered by a plumber who shaved a bit off, so it is now level with the base of the tank. I have tried swearing at it multiple times, in two languages, but that did not work either.
It flushes well, but then carries on trickling unless I hold the float valve up, when the syphon does that deep glug glug and stops. The actual tank is a "new Reverso" (not a good name for a loo!) and is made of bakelite, and is fixed to a 3 foot wide stone wall, so I dont want to change it.
How much flush pipe should be in the tank? Is this the problem? Any ideas welcome!

 

[HERTS P&D]

I have tried swearing at it multiple times, in two languages, but that did not work either.

This normally works, the next thing to do is post some pictures.

Andy

 

[Old Boar2]

These any help? Sick of fiddling with it!

 

[CountryFan]

Can you take a photo next time it flushes or is it constant?

 

[HERTS P&D]

I believe the water coming in is fast enough that after you have flushed the toilet the water keeps flowing through the sysphon into the bowl.

Try raisng the syphon to the next level.

Andy

 

[Old Boar2]

Thanks Andy - I have tried at every level. The higher it goes, the weaker the flush, if that is any use. The yellow things are a right pain to get in, as there is no room for my fingers! The syphon does not reset no matter what level I set the gubbins!
Does it make any differene how high the flush pipe is inside the tank?

 

[CountryFan]

The yellow things are a right pain to get in, as there is no room for my fingers!

Try splitting it, I'm sure it's a serviceable type

Does it make any differene how high the flush pipe is inside the tank?

Not normally

 

[Old Boar2]

Thank you for your replies. It seems I have a cistern that defied the laws of gravity! I shall now find a small tree and beat the loo into submission, unless anyone has any ideas!

 

[CountryFan]

Which Syphon was removed out of interest?

 

[ChrisJP]

It flushes well, but then carries on trickling unless I hold the float valve up, when the syphon does that deep glug glug and stops.

That suggests to me that the water level in the cistern is too high when the float valve cuts off. If the water level is at the same height as "the bottom of the siphon top" (so to speak) the siphon will keep running. That's why when you hold the float valve up the siphon stops.
Apologies if you've already done this, but move the ball down a bit on the float valve arm and see if that stops the siphon running. If it does, you then need to find the optimum position for the ball that provides an adequate flush but doesn't overflow the siphon.
If you've already tried all this and somehow the siphon keep running, then I'm mystified and can't help further!

 

[ChrisJP]

Oh.. and siphons don't have "flappers" so I'm not clear what you've changed here.

 

[Old Boar2]

ITs a Dudley Turbo 88. The flapper is on the end of a yellow rod that is pulled up by the loo handle. Thanks for the suggestion Chris, just tried putting the ball at the lowest position but the syphon still kept going. I think I may have invented perpetual motion!

 

[ChrisJP]

Ahh...sorry I misunderstood - I think the flapper is more usually known as the diaphragm, normally made from polythene and supported by a plastic grid, so it can initiate the siphon and then allow water from the cistern to flow past it.
Flapper is the usual name for the valve at the entry to the flush pipe on non-siphon cisterns that is pulled upwards to flush the toilet and which then "flaps" downwards to reseal so the cistern can refill. The usual arrangement in US toilets, not so common in the UK, though push buttons to release the valve are now the norm for UK toilets.
As for your perpetual motion siphon - I've run out of ideas!