34 pic 4 dash pot

[hex]

Sooo

Replaced my carb with a machine 7 rebuilt one from Germany, it’s a 34 pic 4 on my CT t25 1.6, had it set up by my normal guy but from the moment of picking the bus up somthing wasn’t right.
The revs can take forever to die away or even stay on making breaking a tricky business. Now I at first it seemed like the accelerator pump arm was the issue as it was missing busings that my old one had causing it to stick. But now after fixing that I’m thinking that maybe it’s the dash pot unit these carbs have powered from the air cleaner box vacuum.

So the question here is what can I do to fix/prove this so I can sort it or get the carb swapped out for a working one?. I tried checking the little one way valve that’s inline before it and that seems ok. I’m guessing I could just simply block it off and drive without it and if the problem stopped that would be a clear sign wouldn’t it?, unless anyone else has a good idea?.

Also can you still buy them or can I services it at all, looks like I can’t open it. Do they serve any “real” function, I know they help emissions and help stop stalling (is that at cold though as never had any issues with a quick throttle off causing stalls on my old 34 pic 3’s before?) but how noticeable or worth while is it?.


Thanks guys

[bigherb]

Set it up properly first. And make sure you have the vac hoses fitted correctly.

[hex]

Thanks big herb I will have a look at this, think I may have spotted a vacuum pipe issue straight away

[hex]

So I have had to refit my old carb as the new one was so bad it wasn’t usable, and the old one works much better and even has more power. The strange thing was that as I took the control valve (at the back of the carb bottom of float chamber) vacuum pipe off there was fuel in it???, surly that runs to the air box thermostatatic valve and a should have fuel in it right?

Can someone explain what that’s all about for me

[bigherb]

No, it should not leak fuel into the pipe, it is a temperature compensator valve for the accelerator pump quantity. The older version used a wax capsule.