GK73A Diaphram Hard?

[Callist]

Hi,

I have been stripping the carbs from my GK73A project and I have noticed when pushing the slides up they stay stuck up.. Once I opened the top of the carb and removed the diaphram and slide i could feel that the rubber diaphram seemed hard.. (A lot harder than my GSXF 750) *This is the only other bike carbs I have seen/opened*.

Is this normal or not? The slides just wont return to the down position.
Is there a way to soften the diaphram rubber, or replace it for a decent cost (and where?) any info on getting this issue resolved would be very mcuh appreciated! thanks :)

[Variablevalves suck]

If theyve been dry for a while they may feel hard, you can soak them in a little fuel and see how they go.
Wemoto use to do them at about £20 each but dont list them at the mo so try NRP.

[Callist]

Thanks for the info, I will give the petrol soaking a go, if no luck I'll buy replacements from the NRP site, Cheers!