so Richard Brookman was, like...
> The dear old Series let me down big time last weekend on an event, so
> this weekend I am trying to sort it out but with no success.

<snip tale of woe>

Having checked and adjusted everything else on the vehicle (after all a
6-month-old carb can't be THAT bad, can it?) I finally did what I should
have done much earlier and swapped the pattern Zenith for a known good one
(thanks, Dave's S2 trialler). Immediately the S2a ran like a sewing machine
lubricated with Bailey's Irish Cream. Doh! Thanks Dave.

Given that the vehicle started to play up during a slow off-road trek in
Mid-Wales, and then got a whole lot worse while doing a lot of crawling and
idling on a treasure hunt, I'm inclined to think that it's underbonnet heat
that has caused the carb to warp beyond repair. It was fine on main road
driving, however fast, presumably because the air flow round the carb was
enough to keep it fairly cool.

I'm now trying to source a new carb, but they are like hen's teeth. Still,
at least I know what I am looking for now. Oh bugger, now the MoT's run
out.

Thanks to all for the replies.

--
Rich
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Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)