Stuck mixture screw

[The Shaggy D.A.]

Put the legal exhaust on the Savage for the MOT next month, so wanted to get the mixture set right as it was running a bit lean with the straight through jobby. Problem is that it's stuck fast, won't go in nor out, and being brass is starting to just mangle up. I've soaked it in WD40, but it's not got much inset for there to be any pooling so I can leave it overnight.

Don't want to try an impact driver, so considering using an extractor. I've not got any (saw a £10 set in Maplins, looked like it was made of chocolate and is the same set you can get for £6 on eBay).

Any recommendations, or hints and tips to get a stuck mixture screw out of a carb?
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Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[nowhere.elysium]

I'd be tempted to see if freezing the carb would help to crack the seal on it.
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'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[Robby]

Penetrating oil or freeze and release. Don't use an extractor, they just make a mess.

[Casper]

Someone on another forum had the same problem. A strip down and overnight soak in diesel did the trick

[Budgetboy]

[temeluchus]

The idle mixture screw won't solve all fuelling probs, it will only sort out leanness at idle and just off idle. Look at rejetting and adjusting the needle in the long run.
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Some shite cruiser. Now with guns and FREEDOM!

[The Shaggy D.A.]

Thanks for the suggestions, I'll give it a good soak and freeze.

[Robby]

Popping on the overrun is one of the few things that may be caused by the mixture screw, so worth fiddling with. Odd that it has sezied when wound out, they tend to do that when people screw them all the way in with more force than should be possibly on such a tiny brass screw.

Are you coming to the BBQ? Always wanted to ride a Savage.

[reckless_b]

As a bit of a rule of thumb extractors do not remove things that are siezed, especially on studs, if you can shear off a stud head etc with a spanner a much smaller diameter extractor will do nothing but snap trying to turn the sheared stud, usually if the stud or in this case a brass screw will not turn then an extractor is of no use, however, if drilling warms up said article then you have a chance, left hand drills are one of my favorite extractors, if the drill bites the end result can be the screw being wizzed out,if not you still have the hole to try the trad method.
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40 years on the road on and sometimes off bikes with a very recent OFF

[The Shaggy D.A.]

The screw itself looks a lot larger than I'd expect of a mixture screw, in fact if it didn't have a slot in it I'd say it was a brass plug that they put in to stop you fiddling with the settings. Looking at the carb service kit though, it does look like it's just backed way out :-

https://www.nrp-carbs.co.uk/shop/image/cache/data/Suz%20KEY%202/KS-0531_1-500x500.jpg
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[The Shaggy D.A.]

[map]

[reckless_b]

a test of all the top brand of loosening agents against "home made" had the supprising result of a 50/50 mix of atf and acetone being the best
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40 years on the road on and sometimes off bikes with a very recent OFF

[Budgetboy]

[map]

[Bru]

Also, it is quite important that you use a close-fitting screwdriver for that screw head. I recently destroyed an internal jet by using an undersize screwdriver - my impatience cost me.

It wouldn't hurt to tap the back of the screwdriver - when it is on the offending jet) with a small hammer or spanner, as the shock may help to break up the crud around the thread.

[The Shaggy D.A.]

Not sure if this would fit my carb (BS40) but bloody hell, £26 for a screw? Sheesh.

https://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=300719311806&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5