Engine: 2.1 Carb B21A: Pierburg strip and clean part 1

[wisty]

Thank you. It looks like just 4 bolts hold it to the manifold.

[Othen]

Bob is spot on.

Don’t try cleaning the carburettor while it is in the motorcar, the chances of dropping some small part would be too great. Have the diaphragm and a tin of carburettor cleaner to hand before you start, then take a load of photos of everything from all sorts of angles with your cell phone.

From memory: there is a big circlip holding the air intake on, remove that. Then take off the fuel pipe and the vacuum pipe. I’m pretty sure the throttle linkage is just held on with a clip (don’t lose it) and the choke by a single screw. Then there are just the 4 nuts securing the carburettor onto the studs. Break the join very carefully so as not to damage the gasket if you can (get a sheet of gasket paper (or a cornflakes box) just in case).

The carburettor should then come off pretty easily. Take the dash pot cover off and pour the oil out. Then just follow Bob’s guide.

Good fortune.

Alan

This may help: https://www.volvoforums.org.uk/showp...postcount=3773

[wisty]

Thanks Alan. I wouldn't have known about the gasket to the manifold.

[Clan]

Originally Posted by Bob 1967

Pierburg started acting up and I had sourced a Stromberg fairly cheap .
I was going to do a swap , but as can be seen...


It's the mirror (fuel feed and throttle are on opposite side) D'oh!
So that's not going to work (you certainly get what you pay for!)
Okay ,rebuild kit ordered I gave the outside a clean .
First off the Damper and plastic cap followed by the Pot cover



The throttle slide was manky with carbon/soot and the Needle was covered in green crud ( I would find more later)

The chamber wasn't much better.


Float chamber base remove screws and remove


More crud, it's a wonder it ran at all


Remove the clip centre of pic ( it comes out with no effort ,just fingers)


And releases the float bowl, clip is at top left beside float

With float removed chamber has green crud deposit (possibly from moisture/or condensation from breather ??)


I didn't want to strip any further until I had the kit in hand ,so on with the prep.


If you look closely as I did you will see lines that look like cracks ,but they are actually bad casting marks.
They were also apparent in the chamber top, which wouldn't be good for the diaphragm (It wasn't ,it had a similar pattern and was perishing)




all cleaning done with a non Dremel with a wire cup brush.
I am tempted to grind the bad casting ridges to a smooth finish.

More to follow.....
Bob

I overhauled dozens of these back in the 90's goodness knows what state they are in now 30 years later.

This is what needs doing:

A new Genuine Diaphragm and white plastic retainer, these distort, and get the metal plate that goes on top for the 4 screws to press on. These never seem to get put back if someone is not familiar with them

A new needle ( PN from memory)

A new jet assembly, these both wore over after 5 years giving a rich idle .

A new float bridge piece, the little white plastic one that slides in to hold the float in . they collapse and allow the float level to go high , very rich mixture!

I would put money on the external air bypass vale not working , the silver one with the J shape black rubber pipe on. best replace that too...


dont forget the rubber O ring around the CO adjuster screw

One last thing a new float chamber Gasket and get the CO set to about 2% on a mot emission tester.


apart from that the throttle spindle should be fine.