The hose that goes into the black plastic housing? That's the crankcase ventillation hose.
The mixture screw is (I think) located in the base-plate of the carb. If you took picture 2 from a lower angle, you'd see it. Post up a picture like that, and I'll circle it for you.
kloppen wrote:The ventilation hose, is it suppose to come misty smoke that smell like petrol out of it? The crankcase, what is that?
Not really...when did you last clean / replace your flame trap?
kloppen wrote:
The idle circuit mixture screw (as far as I'm aware) is behind that throttle spindle, almost exactly where you've pointed to. I'll try to get a picture of mine tomorrow.
The flame trap...I'm not exactly sure where it is, but I think it's in the box on the other end of the pipe which runs into the plastic moulding on the top of the carb. You're looking for a clear plastic 'filter' around the size of a mid-size coin in the middle of that box.
The mixture is a ratio of fuel to air. You're adjusting the amount of fuel bled into the air stream on the idle circuit, therefore altering the air/fuel ratio (ie: the mixture).
Usually clockwise goes leaner, ie less fuel - think of it as screwing down a tap.
Unless you have an exhaust gas analyser you`ll have to do it by feel.
Screw it in until the engine starts to misfire and begin to run badly. (Mix too weak)
Blip the throttle a bit to settle it and slowly screw it out until the engine begins to "hunt". (Mix too rich)
Somewhere between these two settings will be your sweet spot - gently feel around it blipping occasionally to settle it until you get it just so. Usually the engine speed will vary a bit during adjustments and the sweet spot will be where it is the highest.
All a bit Zen really and one of the reasons I prefer a carb.
Natch all of this with a fully warmed up engine - an italian tune up beforehand is often helpful
Find a good bit of road and basically thrash the pants off of the car for about 1/2 an hour, getting it good and hot. Blows muck out of the engine, removing carbon deposits and the like that can build up if the car is mostly used for bumbling around town.
.. ouch fuel economy
