Adjustment Solex 28PICT-1

[Ovally]

Hello,

A while ago I bought a carburetor 28PICT-1 that has been cleaned and reconditioned.
Ignition and valve clearance are OK.
The engine is warmed up / automatic choke is fully open.
The idle speed is set to 850 rpm.
When I turn in de volume screw to the right, the engine speed doesn't start to drop but the engine runs faster and faster even with the screw all the way in.
Normally the engine must stall (I think) but he doesn't.

Is this a bad carburetor or can it be something else?

Regards.

[glutamodo]

Yeah, sounds like something is not right in there. That mixture screw should kill the idle if screwed in all the way.

BTW, the original factory idle speed on the 1200 engine with the 28PICT-1 was actually 550RPM. VW revised that to 750 RPM later on.
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[Ovally]

Thanks Andy, there is definitely something wrong with the carburetor.
It makes little to no difference if I turn the volume control screw further out.
I put the idle speed a little lower and made a ride.
The car stutters when accelerating.
The mixture is too rich, the spark plugs are black but dry.
I will open the carb to find out what is wrong.
Could it be that someone has tightened the volume control screw too much and so damaged the carb inside?

Regards, Armand

[mukluk]

Sounds to me like the main jet is likely too large, possibly the idle jet as well.
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[EverettB]

First, pull out the mixture screw and see if the tip is broken off.

If you screw it all the way in and the car does not stall, it is possible the idle jet is too large or worn out.
I have had that same problem and found the idle jet was worn very large from wear or from someone drilling it larger.
I replaced the jet and everything worked correctly.

Maybe the main jet too, as mukluk said above.
I don't have experience with that as a source of the problem myself.
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[Ovally]

Thanks, I will check the mixture screw, the idle and main jet.

Regards, Armand

[sgmalt46]

check your fuel pressure. alot of pumps now are now putting out too much pressure. ive seen over 6psi anything over 3psi will over ride the float valve and make tuning impossible .jetting wont fix it.
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[Helfen]

[Ovally]

Tried another 28PICT-1 from a friend : no problems with that, exactly to adjust as described in the VW manual : RPM 550 and CO 3 %
I wil open the bad "reconditioned" carburetor this winter and try to find out what is wrong.''

Regards, Armand