Solex Carb Hell !!

[Hippy_Boy]

I've got a 1984 1900 petrol T25 running a Solex 34 pict 5 carb which is giving more grief than I thought possible, is there a viable alternative to this carb within a decent price range or can anyone give me the correct factory basic settings for it ? Its ticking over ok but doesn't seem to have enough power to drive without spluttering & then cuts out, I've checked the jets etc & nothings blocked, fuel filter changed & auto choke set according to Haynes manual, is it possible to bypass the auto choke to see if this is the trouble ?

[kevtherev]

Hello and welcome...
I believe solex carbs had air leak issues when they get older and worn
Peirburg 2e3's were fitted to WBX engines, better carb in my opinion.
If your solex is standard fit then I guess you'd need a manifold to go with it

have you checked for induction air leaks?

[Hippy_Boy]

Thank for getting back, yeah no leaks that I can detect, I've got a feeling its the auto choke but being a relative novice working on these I'm not sure.

[kevtherev]

this your carb?

[Hippy_Boy]

No that's a pict 3, mine is definatley a pict 5, I'm assuming they differ in several ways ? IThe body is stamped pict 5 so thats about the only thing I am certain about at the minute !

[kevtherev]

OK is your choke electric or water temp controlled?

[Hippy_Boy]

Electric, its got a control unit air filter side of the carb that I've set according to the manual, as far as I can know it heats via the air flow then opens the choke accordingly but om the opposite side where the cam etc is it just seems to reset to fully closed whenever the engine revs, hot or cold.

[kevtherev]

Ok ...
once the intake duct is removed.. from a cold engine and looking from the top, you should not be able to see down the venturi, a flap should partly cover the hole restricting the airflow. This is the choke flap.
There should be a small gap.
As you accelerate the gap should widen as the flap is moved/opened with the vacuum from the engine

If it doesn't then the mechanism to do that has failed and the engine is overchoking

[Hippy_Boy]

OK, thats what it seems to be doing, when it returns should the fast idle cam return to exactly the same position also ? Cos I set that using some inmfo from another VW forum but when it returns it sits on another step of the cam, sorry if these are idot level questions but I am new to working on these carbs.

[kevtherev]

[Hippy_Boy]

Also there seems to be a few pict 3 & 4 carbs about for sale, are they interchangeable at all ? Swapping jets etc ?

[kevtherev]

what does it seem to be doing ...moving or not?

[Hippy_Boy]

moving, the settings I was told to use are air bypass screw 2-2.5 turns out, hold choke flap open then wind fast idle screw onto last step of cam then 1/4 turn more, are these correct or am I starting from the wrong settings ?

[kevtherev]

OK it opens... that rules out a whole heap of crap.
Next check that the accelerator pump works.
as you press the accelerator it should squirt neat fuel into to venturi.. this is the transfer jet, it helps the engine go from tickover bleed jets to main jets thus preventing stall

[Hippy_Boy]

Not my day today, bloody internet just crapped out too !
The pump seems to be working too, could it just be radically wrong settings on the carb itself or am I simplifying things too much ?