Hi Larry,
As luck would have it I managed to talk to a fella here in Oz who is also a wealth of knowledge with these most perplexing beasties and he suggested the same thing. Also suggested a few other things to check, like the hose between the regulator and the crank case that supplies pressure to the regulator. You know I had already changed it but thought, well can't hurt to change it again with fresh hose off the roll. Bugger me if the engine now seems to be running a treat, all settings are now back to where they should be, but the real test is in the air and that will have to wait til the weekend. Will let you know the out come. Thanks heaps for the info. This is the first time I have posted to this forum, it's great will be back for sure.

Cheers
Jeff