HS2 Carb part ID

[rocco]

This is a bit embarrassing but I'm going to ask anyway because it's messing with my head too much.

I stripped and cleaned my carb last week. New needle and seat, new jet tube, gaskets.

I have this small collar left over that I originally thought was part of the jet tube (25) but I'm not convinced. I've checked through the manual which isn't overly detailed and also the exploded parts diagram but still can't ID it. It's not 34 either.

Does anyone here know where this tiny (approximately 2-3mm) piece came from please?

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20221011_200657.jpg (76.08 KiB) Viewed 1713 times

[NETTIE]

It reminds me of the collet at the end of the lower fuel tube ??

[rocco]

If you mean this piece then yes, it looks exactly like it but it's far smaller.

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The closest I've come to finding it via an online search is this, although it is definitely not 1x1x1cm in size

https://www.101parts.co.uk/shop/engine/ ... for-lever/

[philthehill]

I do not recognise the part in your photo above.
Below is an exploded Burlen Fuels SU carb suitable for the Minor and I cannot see the part in the exploded view.
https://sucarb.co.uk/carbspec/carburett ... s/id/1907/
Are you sure that the part came from your SU carb?

[rocco]

Philthehill does it again!

I think it might just be the unnumbered part in that diagram that I've pointed a red arrow at.

Carb_Unknown_Part.jpg (21.9 KiB) Viewed 1684 times

If not, I bought another one on eBay a few weeks ago so I'll have to strip that one down and find the little bugger.

I'll update as soon as I figure it out. Just makes me laugh that the smallest, most insignificant looking part on the entire car has stumped me first.

[NETTIE]

That looks like a standard washer and not brass coloured like the other components good luck

[svenedin]

Is this photo diagram any use?


https://sucarb.co.uk/carbspec/carburett ... s/id/1907/

[rocco]

Thanks. That's the diagram and link that Phil shared a few posts up. I think it helped but I still haven't found a definitive location for it, but I will.

[svenedin]

I thought it might be part 28C which is not in the diagram Phil posted. I just had a spare carburettor out to look at it but I can't see where you part comes from.

[rocco]

Unfortunately not. Part 28C is a washer that looks like this, according to that website.

28C.jpg (28.31 KiB) Viewed 1604 times

[svenedin]

OK. Let's hope it's not essential. I am going to be rebuilding an HS2 soon (so that I have a spare complete carb) so if I see this piece before you find the answer I will let you know. It looks like a bush of some kind and if it is so small, whatever shaft goes through the hole is also rather small.

[rocco]

Thanks, appreciate that. I think it's just an eye for one of the small cable holes. I didn't find it yet on the other spare carb I bought because I've been working on the head this weekend. Valves came out easy peasy, just one stud that's for the small tap valve at the back is being a pest. Going to heat it and use the new nuts to get it out.

[philthehill]

I hope that you have better luck at removing the heater tap stud than I had. Even heated to cherry red it would not budge. I might have to drill out the 1/4" stud and replace with a 5/16" stud.

[philthehill]

I hope that you have better luck at removing the heater tap stud than I had. Even heated to cherry red it would not budge. I might have to drill out the 1/4" stud and replace with a 5/16" stud.

[MontysDad]

I hope that you have better luck at removing the heater tap stud than I had. Even heated to cherry red it would not budge. I might have to drill out the 1/4" stud and replace with a 5/16" stud.

Rather than go up a size for the stud,have you thought about helicoil?

I had the opposite problem to you - my heater valve stud had stripped threads so it wouldn't stay in at all. Bought a helicoil kit off ebay, drilled and tapped to the right size and fitted the helicoil, now I simply use the normal size stud.

[rocco]

Oh cheers, now I'm worried isn't going to budge and the thread is going to ruin it!

I don't know what helicoil is (until I look it up) but it sounds good and something I'll keep in mind if I even up stripping threads.

There has to be one stud that give us grief, especially when all the others come out relatively easily. It wouldn't be a challenge otherwise.

[philthehill]

If the threads on the studs holding the tap in place are ok, why not just leave them as they are. It is not an imperative that the studs have to be removed when overhauling the head.

[rocco]

The only reason to remove it was to be able to get the remains of the old gasket up, that's fused itself to the metal surface.

I think it gets to be a battle of wills. I want it out and so it will come out even if it makes more sense to leave it.

[philthehill]

Soak the old gasket in gasket remover fluid and the gasket will dissolve.
https://www.ebay.co.uk/itm/195329631183 ... R-SEqc_8YA

[oliver90owner]

A wire brush in a drill/angle grinder will normally deal with bits of old gaskets.

Left-handed drills often come to the rescue, for me, if/when a stud like that breaks off.

Over-sized studs are best reduced to the normal diameter - or difficulties often arise with enlarging the clearance hole or dealing with a larger nut.