Tired air cooled thermostat???

[tobzman]

I've asked this before but didn't get much response, as it's more of an issue now I thought I'd try again.

I replaced the thermostat on my 2L Aircooled earlier this year, I tested the one I fitted by heating it, it expanded and contracted and the fluid could still be heard inside when shook.
However when I connected it all up the tension in the flap return spring caused the stat to be stretched to its full extent even when cold.
I checked this morning before starting (it was below freezing outside) and the flaps were in their fully open position so the stat definately isn't closing them when cold.
My question is can a stat become a bit tired when it's old and lose it's ability to contract against the tension of the return spring???
I tried taking a turn out of the return spring but then there wasn't enough tension left to hold the flaps open anymore.
Has anybody come across this and what was the solution???
I feel I really ought to sort this out for the good of my engine through the coming cold months.

Cheers
Toby

[Hacksawbob]

https://club8090.co.uk/wiki/Pe ... thermostat

[tobzman]

Cheers Bob I'm very familiar with those articles on the wiki they were very useful to understand everything initially. AFAIK everything is setup correctly but the stat just doesn't have enough pull in it to overcome the return spring