Well, for the most part, lpg systems are constructed from stock gas fittings, working on gas flow, so more likely to follow convention than not.....
But we dont have the metal infront of us, you do, and even if we did, we'd probably not be much more informed than you........
At some point, you gotta give it a tweek and suck-it-an-see!
Gowarn! Tell you what, go get an EZ-Tune plug..... then you can watch the effect twiddling has, 'live' in the little sight glass!
Got a tuning plug thingy with a glass top, never thought of that , I'll dig it out and have a go.
I've started twidling allready and advanced the ignition a bit and she runs a lot better. Just need a light throttle now to run up the speed and she seems to have a lot more power. Cruises on the motorway at 60 hardly touching the throttle so should be using less gas.
No pinking on petrol either so may even need a little more. We'll see
Mixture setting on the old SU? You screw the main jet up and down? Clockwise screws it into the carb-body, lifting it around the needle, closing the jet, making it 'lean', anti-clockwise, lowers the jet, pulling it away from the needle, ritchening it up.......... (unless they put a see-saw arrangement on later versions or something!)
Yes, the old HS carbs did, as you say, screw up (in) to weaken but the later type of HIF as on my 3.5 have the floatbowl underneath the jet and the mixture screw on the side screws in to richen as it lowers the jet by screwing it in and raises the jet by screwing out to weaken.
Do you mean the idle setting screw, or 'primary air jet'? Think that works contrary, becouse the tap is controling flow of air over the idle jet, not the flow of fuel through the jet, so it's still clock-wise to close, but closing chokes air-flow, not fuel flow, so the mixture goes air-weak, or fuel ritch.... if you see what I mean! (Seem to remember a lot of webbers were set on air not fuel, so closing taps meant ritch fuel)
