fishboy Posted February 9, 2012 Share Posted February 9, 2012 (edited) Hi all, So I'm rebuilding my Hitachi EA82 carby according the Gregorys workshop manual and I've a hit a snag in dismantling the top cover. After removing the float, I am supposed to remove the needle valve seat assembly (the brass colored thing in the image below) "using a screw driver". What do they mean by that statement? Am i supposed to just jam a screwdriver down the side and try and pop the whole assembly out? Or am I supposed to use a large slot screwdriver to rotate/screw it out (there is a slot in the top)? If it is the latter - I tried and tried to unscrew this (anticlockwise) but it just started burring the slot. Anyone done this before and know how it is supposed to be removed?? Edited February 28, 2012 by fishboy New question added to thread Quote Link to comment Share on other sites More sharing options...
Quidam Posted February 9, 2012 Share Posted February 9, 2012 Hi, Good description, and yes, anticlockwise it screws out. Try penetrating oil or throw some heat on the carb body. First one of these I did, I selected some of my screwdrivers and custom ground them to fit all the various screw slots. Like the power valve, and the one you're working on. Often times, a tight precise fitting screwdriver and just bearing down on it and turning may pop it out. Without destroying anything. On the other hand, I've had a few where I dribbled some weak acid solution around them to get then loose. Let us know how it goes. Doug Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 9, 2012 Author Share Posted February 9, 2012 Thanks Doug! What's the best way to apply some heat - with a hair dryer? Quote Link to comment Share on other sites More sharing options...
Skysm182 Posted February 9, 2012 Share Posted February 9, 2012 Thanks Doug! What's the best way to apply some heat - with a hair dryer? Hair dryer won't get it hot enough. You need a handheld propane torch Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 9, 2012 Author Share Posted February 9, 2012 Ah, okay. Where would you apply the flame - directly to the aluminium or to the brass bit? (sorry - I'm new to this..) Quote Link to comment Share on other sites More sharing options...
Skysm182 Posted February 9, 2012 Share Posted February 9, 2012 Ah, okay. Where would you apply the flame - directly to the aluminium or to the brass bit? (sorry - I'm new to this..) I have never personally done it so maybe someone else can chime in Quote Link to comment Share on other sites More sharing options...
Quidam Posted February 9, 2012 Share Posted February 9, 2012 I've used a propane before, just on the aluminum. It doesn't take much to expand it a little. Doug Quote Link to comment Share on other sites More sharing options...
BratWarrior Posted February 9, 2012 Share Posted February 9, 2012 BIG screwdriver. It'll come out. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 9, 2012 Share Posted February 9, 2012 Yeah you need a large screwdriver. Also often helps to give threaded items like that a sharp blow with a hammer/punch - breaks the corrosion bond. An impact screwdriver would be perfect but you would have to custom grind a bit to fit that seat. If it were really stuck then I would probably sacrifice a socket extension and grind it to fit that slot then use the impact driver. GD Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 9, 2012 Author Share Posted February 9, 2012 It looks like I've burred the slot on the assembly bit trying to free it. Is this going to affect the function of the carby? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 9, 2012 Share Posted February 9, 2012 No - as long as the needle can move freely and will seat in the bottom it will be fine. The top where that screwdriver slot is located is not a critical surface. GD Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 10, 2012 Author Share Posted February 10, 2012 Apologies for being pedantic!...but are you sure I can apply a butane torch flame to the aluminium? Wouldn't it quickly melt/deform he aluminum top cover? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 10, 2012 Share Posted February 10, 2012 Wouldn't it quickly melt/deform he aluminum top cover? No. It will be fine. Just heat - don't keep going till you melt the thing. Generally speaking, while the flame is technically hot enough to melt aluminium, a casting the size of a carb top would take more BTUs/Hr than a small propane torch can put out to heat it to melting temp. This has to do with flame size, temp, and how much heat you can actually impart to the object being heated before that heat escapes.... aluminium disperses heat very, very quickly. GD Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 10, 2012 Author Share Posted February 10, 2012 Okay, thanks. I'll let you know how I go! Quote Link to comment Share on other sites More sharing options...
ferox Posted February 10, 2012 Share Posted February 10, 2012 Do you have a rebuild kit? Or are you just cleaning and resealing? Whenever I do these with a rebuild kit I just tap a screw extractor down the center bore of the needle seat and unscrew, takes 2 seconds. It will mangle the seat a little bit, but if you are replacing it anyway who cares. If you aren't replacing it, then don't do that. Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 10, 2012 Author Share Posted February 10, 2012 Ferox - I have a rebuild kit but totally thought this seat wasn't included...but on closer inspection it is!! I will definitely give the screw extractor a go in this case. Thanks. And thanks to all for your advice so far! Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 10, 2012 Author Share Posted February 10, 2012 So I just had a good look at the replacement seat and it is a bit different to the existing one. The one currently in the carby appears to have 6 holes in it, whilst the replacement one only has 2 larger holes in it (see pic). Is this likely to cause a problem? Quote Link to comment Share on other sites More sharing options...
naru Posted February 11, 2012 Share Posted February 11, 2012 No,the important part of the valve seat is the size of the hole where the valve seats. Bigger hole = more pressure on the valve resulting in a higher carb fuel level for the same float setting. Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 15, 2012 Author Share Posted February 15, 2012 The seat that comes with the kit has an outer diameter which is slightly smaller than that currently in the carb (existing one is 12mm, the replacement one is 11mm). The inner diameters look about the same though. See pic below. Addionally, as I said above, the replacement seat has fewer holes around the bottom than the exisiting one too. Can anyone suggest whether this new seat is still going to be okay? The only reason I ask is that it looks like I am going to have to destroy the old one getting it out (via screw extractor), since all other suggestions so far have failed including heating with butane torch Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 15, 2012 Author Share Posted February 15, 2012 ...anyone? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 16, 2012 Share Posted February 16, 2012 Looks like it should be fine. I would trust that someone probably tested this combination if it's in a rebuild kit. The inlet needle's and seats always look somewhat different in the generic kits I've found. GD Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 16, 2012 Author Share Posted February 16, 2012 I'd like to trust them, but sadly the company (called "FuelMiser") here can't confirm that it's definitely the right kit. The only information they have is that it should fit Subaru L Series up to 1989 (mine is 1991). They have no other kits to fit later model cars. Quote Link to comment Share on other sites More sharing options...
Quidam Posted February 16, 2012 Share Posted February 16, 2012 ...anyone? Don't know what's been said by other person, but the top diameter isn't important. So long as the threads and seating of the new on is the same. More or less holes won't make a difference either for a street car. Twist it out with an extractor if need be. There is an inlet screen/filter on the bottom of the piece still in the carb. They are typically clogged/on their way to clogging. Doug Quote Link to comment Share on other sites More sharing options...
fishboy Posted February 16, 2012 Author Share Posted February 16, 2012 My goodness. So I got the seat out with the extractors..woohoo! JUST when I thought I was on my way - I go to remove the Primary Slow Air Bleed (see pic) and it's similarly stuck! Only this time I definitely DON'T have a replacement. So...is it really necessary to remove this when cleaning/servicing the top body? Quote Link to comment Share on other sites More sharing options...
Quidam Posted February 16, 2012 Share Posted February 16, 2012 No, it's not that critical that you remove that, just make sure that all the passages connected to it are free and open. If you have a screwdriver that fits it like a glove, push down on it and give it a bump clockwise. You may feel it give a little bit. You can even try tapping the screwdriver with a small hammer. Then try to turn it counterclockwise. At any point you believe you're distorting the slot in the air bleed stop. good luck! Doug Quote Link to comment Share on other sites More sharing options...
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