Torque setting for rocker arm bolt?

[Ken Hanna]

However, those studs are only suitable for the exhaust manifolds.
Not much use for the inlets, which needs to have bolts in order to permit the manifold 'spider' to be fitted...

You can buy oversized studs from ECAS specifically for this job if you didn't want to helicoil

[Highwaylass]

Can I ask you another question, Ken?

On another thread you recommended a 110 main jet for a Solex carb with pancake filter and 2 into 1 exhaust.

I've got a similar set up but a 24/21 carb. Would you still recommend a 110 main jet? I'm getting a lot of popping and banging on the overrun which makes me wonder if things are too rich.

[Ken Hanna]

A 110 is fine for an 18-26 version of the 26/35 Solex, however the 21-24 versions need at least a 125, maybe a 127.5 if the preheat pipe has been removed from the manifold and a 2 into 1 exhaust is fitted instead of the original crossbox.

Popping/backfiring on the overrun indicates a leak in the exhaust system; the closer the leak is to the manifold, the more frequently it will occur.
( The best way to trace any small exhaust leaks is to use a length of windscreen washer tubing, about 3/16"/5mm bore, with one end to your ear and the other end close to any joints which may be suspect.)

Btw, don't mix up the location of the primary and secondary petrol jets. The primary is the one that's hidden away in the nearside float bowl...
https://www.flickr.com/photos/30132857@ ... wf3-9vX9t1

Check the size of the existing jet, which is usually a 120 on those cars sent to the UK.
A cocktail stick is handy for removing those little 'grub screw' jets once they've been unscrewed; ditto when installing one.

Ken

Can I ask you another question, Ken?

On another thread you recommended a 110 main jet for a Solex carb with pancake filter and 2 into 1 exhaust.

I've got a similar set up but a 24/21 carb. Would you still recommend a 110 main jet? I'm getting a lot of popping and banging on the overrun which makes me wonder if things are too rich.

[Highwaylass]

Thanks, Ken! I don't think I have a preheat tube, the manifold is essentially the 2CV spider with the exhaust arms lopped off.

What would you recommend for the other jet?

I might have to replace the carb but I thought I'd try new jets first.

[Highwaylass]

And just one more thing....at 3 1/2 turns out, the idle mix screw seems very wobbly. Is that normal?

[Ken Hanna]

Highwaylass,
doing this a bit back to front, but have you adjusted the closing position of the secondary butterfly yet?
Most high mileage carburettors will benefit from that adjustment, which usually results in the idle system being more responsive, also the idle mixture screw doesn't need to be wound out quite as far.
Depending on the age of the 21-24 carburettor, the screw for that adjustment can be on either side of the carburettor, cable side or alternator side.
One turn back works on 18-26 carburettors, so that's probably a good starting point for a 21-24, although I test it by pouring engine oil on top of the secondary butterfly with the engine on tickover.
If the oil stays put, the butterfly is judged to be sealing correctly.

I've never needed to make any change to the secondary petrol jet; the golden rule when tuning engines is to make only one change at a time, test that, then decide if further changes are needed.
On those cars where I'd increased the size of the primary petrol jet, the owners were happy that the flat spot on a light throttle had gone, performance overall had improved and mpg hadn't suffered.

Btw, just bought one of these, hoping it turns up before I need to set off for Anglesey on Thursday, as that's likely to be another busmans' holiday.
http://www.ebay.co.uk/itm/231245692823? ... EBIDX%3AIT

Even if you overcook things as regards drilling out jets, all is not lost as Mikuni jets will fit in Solex carburettors.
http://www.ebay.co.uk/itm/Brass-main-je ... 3f2c48e339

Ken

Thanks, Ken! I don't think I have a preheat tube, the manifold is essentially the 2CV spider with the exhaust arms lopped off.

What would you recommend for the other jet?

I might have to replace the carb but I thought I'd try new jets first.

[Highwaylass]

Thanks!

I haven't done the secondary butterfly yet but will do that before changing the jet.

[Highwaylass]

Aargh! It is under the carb, in the gap between the body and the manifold. Super-accessible!

[Ken Hanna]

Highwaylass,
if it's got a hex head, with a spring around the shank of the bolt/setscrew, you should be able to get a spanner onto the head
from the side.

If it's the type which has a slotted screw with a plastic 'anti-tamper' cover, snip the top of the cover off with side cutters.
Next, have your assistant apply full throttle, whereupon the screw head should be facing backwards and be readily accessible...
The cutting could also be accomplished at full throttle, come to think of it, but it's been a while since I've dealt with a 21-24.

Ken

( That's all for now, spent most of today cleaning and packing the tools for the fun and games at Anglesey this weekend,
suppose it would be an idea to make a start on sorting out that other stuff, such as the tent, overalls, clothes, food and so on... )

Aargh! It is under the carb, in the gap between the body and the manifold. Super-accessible!

[Highwaylass]

A whole new can of worms....the accelerator cable does not in fact open the secondary butterfly.

If I move the assembly by hand at the carb end, it does open, so the links aren't broken.

off to check how to adjust cables....