Solex 34 PICT-3 adjustment
Basic Tuneup, and Adjustment of the Solex 34 PICT/3 Carburetor
two adjusting screws in the side.
Note: Before we begin to adjust the carburetor, the valves, points, and timing should be set. This is important, and they should be done in the right order, as you start with a cold engine, and end with it warm.
Setting the Valves
Valve adjustment is always done with the engine stone cold.
0.004 inches (0.1 mm)is the factory setting for pre-71 engines. Some folks find that this is too tight after the engine warms and use 0.006 inches (0.15 mm). Thats engines with a number starting B..., D..., E..., F..., H..., L..., or a plain number. (I've always used the factory setting on my H... engine without any problems.)
0.006 inches (.15 mm) is used on 71 and up engines. That's engines with a number starting AB..., AC..., AD..., AE..., AF..., AH..., AJ..., AK..., AR..., AS....
The aim of the tappet (valve) setting is to provide virtually NO gap when the engine is at operating temperature.
Setting the Points
The points are adjusted to .016 inches (0.4 mm). Replace them if the contacts are pitted or the cam rubbing block is badly worn. Add a touch of grease to the cam lobs at the same time. Also pull off the rotor arm and take a look in the centre of the spindle it rides on. If your distributor has a felt pad in there, put a few drops of oil (engine oil is fine) on it to lubricate the distributor drive - don't overdo it though - a few drops only. Some distributors don't have this felt pad - in that case skip this procedure.
The usual timing settings are:
Note: Any VW engine using the Bosch 009 (or other centrifugal distributor) must be set at the maximum advance with the engine at 3000+rpm, and let the idle advance fall where it may. The reason for this is that the 009s vary in the total amount of advance they make, and the maximum advance is more important than idle advance. The normal setting is a max advance of 28-30BTDC. If you have high quality non-oxygenated fuels, you may be able to use 30-32 degrees advance. The idle advance will then usually fall in at about 5-8BTDC. Please note that VW never used the 009 distributor for any of it's beetle models, and so, although it will work, you may get flat spots and poor pick-up when using this distributor.
Now start the engine and warm it up. Take the air cleaner off the top of the carby (if it's the oil filled type be careful, you don't want a shoe full of oil) and check that the choke butterfly is standing vertical. If it isn't, run the engine some more to make sure it's throughly warm, and check the choke butterfly again. If it is not standing vertical, the butterfly needs adjusting or fixing (another topic).
It's important to set the valves, points, timing and check the choke (in this order) before setting the carburetor, they all work together for a smooth running engine.
Note: The correct idle speed is important with the 34PICT/3 carburetor, which is more complicated (and more sensitive) than the earlier types. It has three separate fuel circuits in it (only two in older carburetors), and the 850-900 rpm idle is designed so the airflow through the carburetor is balanced for the idle circuit fuel flow. That's why it has both Volume and Bypass screws in the side (the earlier ones had only Volume screws). This way the idle speed can be set correctly using the Bypass screw without touching the screw on the throttle arm, which has to be set exactly right.
That's it - you're done.
You should now have an engine which purrs like a kitten.