Solex carb

[Ben Baxter]

Right, due to a series of unfortunate events my Herald is now seriously out of tune, and it was running so well before too.

Firstly I think there may be some dirt somewhere between the fuel pump and the carb, any idea where it might be lodged?

Secondly, could someone be so kind as to explain how to set up the Solex in layman's terms. The Haynes manual isn't the most clear on the matter. Well aware that they're not the most adjustable units but what is the general method for getting the slow running/volume right? The volume screw got knocked the other day and don't want to go upsetting it further without knowing how to go about getting it right again.

Assume I haven't got a vacuum gauge for the second.

[Pete Lewis]

most likley place for loatin debris is just above the float chamber needle valve unscrew it and look behind it.

adjust the mixture volume with idle as in book around 650/700 rpm thats tickety boo not va va room    like nice and slow,, if its too fast the idle mixture will be out of action,
just screw the idle mix screw in and out to get the best idle  if it speeds thing up unscrew the idle stop to slow down. then recheck the mix screw,  when you are happy its at its best screw mixture screw in to drop the idle speed just a tad, 25/50 rpm is is just decernable,
that means you are set at the weak end of the best setting
the idle mixture screw has no effect on normal running it only operates at idle when the throttle plate is closed or only partially open a small amount.
if you take the carb off you can see the tiny idle metering holes in the side of the bore just where the throttle plate closes    Peter

[Ben Baxter]

So screwing in is leaning off the mixture right?

And I want it so that it's just screwed out enough so that it isn't stuttering? (I don't have a rev counter either!)

General idea is:

Screw in volume till stuttering then back off a bit
Back off throttle stop
Repeat

Yes?

[Pete Lewis]

you got it  ,,,,, stuttering is to far so back 2 bits ,, if you get a flat spot when just taking off back it another bit,,   see all these bits make herald a happy bunny

you cant mess up the main mixture or your economy as  this is fixed by jet sizes you are only playing with the idle circuit    so happy twiddling   Peter

[Ben Baxter]

Right oh, shall get that sorted then, looks like the flat spot when driving may have been dirt in the float chamber. Going to keep an eye on it, hopefully there's no more in the pipes but not counting on it.

Now I just need to figure out what the strange metallic clunk was that occurred when in reverse and letting the clutch out, didn't like the sound of that one at all.

[Clive]

If not already mentioned it is worth fitting a cheap plastic fuel filter in the fuel line. Stops a lot of crud, in fact it can be shocking what collects.

Clunking in reverse? maybe wear in the diff (jack up, see how much you can turn the propshaft before the wheels turn, then try turning one wheel and see if there is play there. Also gearbox mounts and so on.

Clive

[Pete Lewis]

b, dont forget to check the wheel nuts ?  Peter

[Ben Baxter]

Short and simple solution to the clunking - also solved the clutch judder:

The nut that goes through the bellhousing holding the exhaust on was ridiculously loose - looks like that was the cause of the problems as they've stopped now! Went round nipping up pretty much every nut and bolt I could find today, loads of the sump ones were loose too.

Petrol filter is on my "to do" list, mustn't keep forgetting about stuff like that.