Nice one.

Alkie,
now that you've uploaded those pictures of your carb, it confirms that this guess from last week was correct...

"If the ball and spring have managed to escape, it suggests that the stop which limits forward travel of the choke cable and fast idle cam may be missing."

A 6mm bolt about 30mm long makes a suitable replacement for the missing part, item 24 in that line drawing.
The bolt will stop you having to worry about the cam being able to move too far forwards and allow the ball and spring to escape.

Goodness knows why those stops are ever removed in the first instance, maybe idle curiosity?

ken

Ladies and Gentlemen, I'm here all night...

Been searching through my parts box for a suitable 6mm bolt to no avail, off to B&Q next chance I get for some threaded rod, thanks for the advice Ken

What a difference a jet makes...

I swapped the 120 primary jet for a 107.5, correct for the 26/18 carb. I don't know whether my experience has been clouded due to only ever having run it on an oversize jet previously, as the car feels so sluggish and bogs down in the first 1/4 of accelerator travel. Only when warmed up does it start to return to being sprightly, but it still feels strangulated. As I said its probably due to the fact my only reference was driving the car around with, as Ken rightly said, with a jet that big, almost with the choke on all the time, this is probably 'normal'. The exhaust note has changed too, due to it obviously getting less fuel now.

Its either the jet is too small, or its fine and I'm not used to it yet, or there's some crap in the carb that is lodged in the smaller jet when I changed it. Is there any chance that I've returned the jets back to factory settings that there are other mods I don't know about? I've noticed my needle valve is a 1.6 and not a 1.7 as it says in the manual, but surely that can't do much?

As Ken said an engine is more sensitive to a weaker mixture, so whether this change of the jet has exposed timing or compression problems, I'm not sure.

Alkie,
what size was the secondary petrol jet?
If someone was daft enough to fit a 120 primary into an 18/26 carb, maybe they also fitted
the 70 secondary from a 21-24 carb, instead of the 87.5 or 90 which should be in there...

If that's OK, could be that you need a 110 primary, which most Dyanes/Amis do nowadays.

Try temporarily disconnecting the 'blown induction' air feed.
If that improves matters, you need a 110 primary jet.

ken

Thanks Ken - I put in a new 90 for the secondary, replacing the 87.5 that was in there, I swapped it as the slot on the front of the 87.5 jet for the screwdriver was all mashed in, so thought why not. ECAS don't seem to do a 87.5...

I'll try and disconnect the blown induction air feed and see what happens. It does feel like there isn't enough fuel getting to it, and seeing as I've oiled the linkages for the carb and generally cleaned it up I thought it won't be down to sticking or flat spots. The carb is in good nick and the butterflies aren't worn.

I'm thinking its quite clear that its the primary jet that is causing problems, once you get over 1/3 on the pedal it really smooths out, and cruising at 65 is now very quiet, but I suppose if I've increased the secondary jet size slightly this may be the reason. At what point does the secondary choke open? (I could check myself but at work and being lazy )

Alkie,
when the primary choke is 'around' 2/3 open, the secondary starts to open.

It does sound like the characteristic 'unleaded lean mixture' on first choke.
All of the Dyanes I work on now have 110 primary petrol jets fitted...

ken

2/3, wow thats much later than I thought, that would definitely explain the lack of power, once again cheers Ken.

Ordered a 110 just in case. Its still sooting up the back wheel, but this may be down to soot still in the exhaust. When it had the 120 jet in it I started it up with the exhaust pointing at a whitewashed wall, it left a round black stain on the wall within seconds, so way too rich, amazing really.

110 jet installed, although it appears to be a 90 jet that has been drilled out. Much much better now, its done the trick. Returned 47mpg on a recent trip down to London and back. Once I was happy with the jet, I adjusted the idle mixture when up to its running temperature and found it was set way too rich.

The heater is now unusable due to the exhaust coming through, time for new valve seals...

valves should have no bearing on it,

fumes are leaking heads or leaking exhaust gasket or flange the leaky oil smoke just lets you know your being poisoned

Sean