Idle Screw Adjustment

I'm trying to tune up my new lpg system on my 88 3.5 classic, but before I get really stuck in i'm trying to return the engine to the standard set up so as to have a reference to work from. Does anyone know roughly how may turns out the screw should be? or how many turns your own is? or does anyone have any advice relevant to this dilema.

Help appreciated as usual!!

The only comment or advise i can give is take it to a garage that specialises in lpg convertions.
i now we all like to tinker on our landies but lpg can be a bitch to set up.

hope it all works out 4 ya
goodluck

thanks for the advice, yet don't worry I am going to take it to a specialist for full set up with all the necessary equipment, however to get it there it needs to be driveable to a degree, the lad i bought the car off didn't know his arse from his elbow and consisdering everything else has been wrongly set up I just assume the idle screw will be too.

Also in addition it seems when adjusting the screw there is no big change to the engine revs and i cant get it above approx. 600rpm, do you think I could have a problem with my vacuum hoses? I want to get it ticking over higher for obvious readings but also because it can easily stall say when manouvering in tight spaces and flicking between 'd' and 'r'.