HI Im new to forum learning heaps just by reading but have a problem with the XF.

Ive been having problems with the idle basically when the thermostat opens the idle shoots up to 2000 and stays there, idles at 700 before you see the temp gauge go up so Im thinking the two are related but could be wrong. Would a slight leak in the head gasket be affecting this. Its a 4.1 xflo motor weber carb with dual fuel, the Lpg system delivery on top of carb retricts the throat of the carb to make the running on petrol rich (black smoke a bit) but thats ok. Hoses are all good, ive tried roating the dizy no results no power.
Ive been living with it last few years but the motor just developed a "tink tink tink" is this a 'lazy lifter?' Now that the head has to come off to fix the lifter and gasket I hope I can sort the idle as well.
Also is it ok to run the motor with no rocker cover gasket on to try and find the dodgy lifter? Possibly wont be able to see which one is stuck any way??
Thanks heaps if you have any info Cheers

You can run them with no Rocker Cover but it's very messy. An old one with the center cut out can help, still messy but not as bad. Good Luck TPVM.