street
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6.2 ft/lbs of talk
Posts: 4,662
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Apr 21, 2006 13:07:16 GMT
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Got a pair of dellorto 40's (DHLA side draughts) that i'm rebuilding. But one of the carbs has its idle mixture screw seized in I've tried everything to shift it, and yesterday I sheared what was left of the screwdriver slot so theres no chance of this thing coming out in one piece now So i'm thinking- should I attempt to drill it out, and then hope to pick the remnants out of the thread with a scribe (cant get hold of a tap for it, cos the threads a silly type) Or, should I leave it in place so the carbs are useable, and just put up with not bieng able to tune one carb properly? The real question is, am I likely to drill the carb into a worthless pile of scrap? Your guidence is appreciated!!! ;D
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Last Edit: Apr 21, 2006 20:55:36 GMT by street
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Apr 21, 2006 13:12:37 GMT
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Can you not use one of those bolt extractors? We had a set kicking round the garage a while back that we borrowed. BAsically drill a small hole through the stuck bolt, drift in the hardened extractor pin, then use the tool to turn it. Trouble is, if the hardened pin shears off it's well and truly buggaroonied. OR, what about drilling the fecker out and finding a bigger mixture screw that has a regular thread and tapping the hole? OR drilling the thing out and helicoiling the hole (dunno if that would work as the hole goes straight through.
The Scort sounds so sweet on those twin 40's I'd hate for you to have to use summat else!
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street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
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Apr 21, 2006 13:19:24 GMT
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That bolt extractor sounds like a good gizmo, cant say i've seen it though! I'll have to look into it, maybe buy one cheap or summat ;D don't know how rough it would drive with one idle screw notadjusted corectly..... if it doesnt effect it much i'm tempted to leave it in......
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Apr 21, 2006 13:56:22 GMT
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I think it will be tooooo small to use a stud extractor kit/set
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Apr 21, 2006 14:58:46 GMT
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The bottom is a spike shape so I wouldn't try and drill it, you'll just fill it with curse word and have a bit stuck in the bottom. What's left of the screw to get hold of or has it sheared off flush?
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street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
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Apr 21, 2006 15:23:36 GMT
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Yeah its pretty much sheared off flush. They're the type with a 'tower' around them, so no chance of getting anything 'on' it so to speak. Maybe I should source another good one... but i'd rather repair this one though as they don't come up cheap So is drilling out a definate no-no then?
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Last Edit: Apr 21, 2006 15:24:44 GMT by street
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Apr 21, 2006 15:30:21 GMT
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You might get away with it if you could weld a small nut onto the top of it. You'll need someone who is very good at welding to tackle it and TIG would be better than MIG so you can aim the heat down onto the rest of the screw. The heat will hopefully break it free and the nut gives you something to get hold of. Never tried it on something that small though so success is a gamble.
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Apr 21, 2006 16:16:57 GMT
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It is possible to weld on a nut to the top, TIG will probably be the only option though as mig isnt acurate enough.
And don't use a bolt exctractor that has the taper and backwards thread, i got a set of webers cheap at an auto jumble. Turned out they had creased a screw in the bottom and i couldent shift it, que screw exctractor! Well all that did was crack the cast housing and ruin the carb, fortunatly i sold them back to the dodgy geezer the the next auto jumble for more than i bought them for! hahahahah sit and swivel scum bag!
J
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Apr 21, 2006 16:24:11 GMT
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Yeah its pretty much sheared off flush. They're the type with a 'tower' around them, so no chance of getting anything 'on' it so to speak. When we were looking at them a while ago it did cross my mind that we could lop most of the tower bit off, so we could get some grips on the screw. Not a very delicate method but it may work? With the screw being brass (I think?), is TIG the only thing that'll weld it?
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Apr 21, 2006 16:34:53 GMT
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Ah, I think that's the welding plan out the window if the screw is brass. I assumed it was steel like the Weber ones. Brass will only soft-solder or braze. Yeah, if the tower bit is tall then I'd probably think about shortening it so I got a bit f the screw to grab hold of.
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street
Posted a lot
6.2 ft/lbs of talk
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Apr 21, 2006 16:40:14 GMT
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Yeah its brass Cutting the tower off is an option, but I still don't think it would shift if I got some grips around it, its really well jammed Theres an automotive engineers near me, might take it there and see if they car weld something on the end of it, like you say, the heat wont hurt it either and it should help it free off. I can see me making a pigs ear of it if iI try and drill it, probably curse word up the thread or something! Cheers for your help guys ;D
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Apr 21, 2006 16:40:58 GMT
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I think it's brass, but I'm not 100% sure... I was thinking: Lop off the tower with a Dremel and cutting wheel, heat the thing up a bit with a torch, then have a pop at it with either some mole grips, or a clout with a centre punch. Probably need a new idle screw afterwards though!
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street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
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Apr 21, 2006 20:54:46 GMT
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Success! Bieng the know-it-all jack of clubs that I am, i decided to go ahead and drill it anyway. It shouldnt have worked.... Filled with determination I got out my trusty £9.99 "challenge" battery drill and my poundland drillbits. Not having a vice (I'm working in my flat) I decided the next best thing would be to hold the carb between my knees. Perfect. I then realized I had snapped my smallest drill bit not long ago, so the next size up, 3mm, would have to do. I centre punched where I though the middle was with a screw that has been knocking about the place and the party started. I drilled it through with the 3mm, then went up in size until I got to 6mm, which left about 1mm of the idle screw sticking to the thread. (shows I was remarkably accurate!) I then attacked it with this Dremel tool rip-off from poundland, which was curse word (basically one of those handheld battery operated fan things with some attatchments on the end!) but did the job. Not having a scribe to pick out the remains and unable to find anything suitable to sharpen, I filed down the end of my poundland flatblade until it was narrow enough to fit in the hole. Then it was a case of chipping away at the brass chunk by chunk, which took about 20 minuites, and by then it had freed off enough for my to wind out the remnants with the screwdriver ;D All it needs now is a jolly good clean out and a new idle jet ordering from Dellorto. Well chuffed! ;D ;D ;D
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Last Edit: Apr 21, 2006 20:57:41 GMT by street
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Nicely done then! I need to do the same thing on 3 of the idle screws on one of my Dellorto sets.. (not the ones on the car) Oh, and i figured out why i couldnt tune the idle nice enough, the car only runs on 3 cylinders.... Oops ;D Heh, new distributor cap, rotor, spark plugs, and plug wires are due when i get some cash...
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Poundland is the future ;D
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Nicely done! Might be worth seeing if a Weber idle screw is the same size as they are steel and I've never had one seize before.
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Stu
Posted a lot
Posts: 2,913
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Good stuff, sounds like a nice bit of DIY fixing!
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'89 BMW E30 325i Sport, '04 MINI Cooper S, '09 Volvo V70 D5
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street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
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Apr 22, 2006 12:27:04 GMT
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Cheers ;D Yeah I may look at weber ones, but then I think if i lather the dellorto brass jobbies with grease they should be ok. Its only the previous owners neglect that made them seize Just took the bottom off- looks like a sodding sandpit in there, crapola central! Needs a good clean out and no mistake. No wonder it was running like a dawg
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Apr 22, 2006 15:15:01 GMT
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Nice work! Sod Snap-On, I'm off to Pondland for me tools next time!
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street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
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Apr 22, 2006 15:27:43 GMT
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Yeah you've got to love poundlands tool selection, awesome, all made of toffee! But now that they have started selling 400ml of automotive primer and paint, full resprays have just become in the price range of your average hobo
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Last Edit: Apr 22, 2006 15:31:02 GMT by street
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