Carb Rebuild - Mark in metal question

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oilcan
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Carb Rebuild - Mark in metal question

Post by oilcan »

Spent my black friday cutting through all the junk on the outside of the carbs - good thing is the insides look good (mostly) and don't seem to have been opened up since new. I saw some strange marks in the metal below the butterflies - one below each butterfly. Like indentations? There is nothing on the OUTSIDE of the carb though. Can anyone tell what they are? anyone seen anything like it? And most importantly - ok to just assume it will continue to be ok with them there?

Also - would you recommend taking apart everything which has a screw and can possibly be taken apart, or are there some things ok to leave together? I'm largely following Jim's page at

http://www.goatwerks.com/carbarticle.htm

And it does seem there are a few pieces left in tact - ex butterflies on the shaft?

I appreciate any and all help - kind of a novice here but have decided to throw myself at the pinzgauer and see if i can't learn a thing or two.

thanks
rich
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ako
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Re: Carb Rebuild - Mark in metal question

Post by ako »

Hard to see from your pics but I think the indents you mention are recesses for the studs that hold the gasket in place.

Don't think you will get the butterfly off with special tools to press in new rivets. I just cleaned around mine.
oilcan
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Re: Carb Rebuild - Mark in metal question

Post by oilcan »

Thanks Ako - they are really tough to see. I highlighted one with a ring - I'm pretty sure it shouldn't be there, just not sure what to do about it.

Thanks for looking!
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oilcan
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Re: Carb Rebuild - Mark in metal question

Post by oilcan »

Just realized what this is - looks like someone over tightened the idle screws in the past and drove them right thru the walls...
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TechMOGogy
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Re: Carb Rebuild - Mark in metal question

Post by TechMOGogy »

oilcan wrote:Just realized what this is - looks like someone over tightened the idle screws in the past and drove them right thru the walls...
Wow!
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kdiqq
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Re: Carb Rebuild - Mark in metal question

Post by kdiqq »

Probably wise to seal that up! I'm not sure what I would do in your situation.. maybe put a little gasket maker on your finger and wipe it over? That's insane. What's the end of the idle screws look like?

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edzz
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Re: Carb Rebuild - Mark in metal question

Post by edzz »

I knew I remembered that problem somewhere. :(

http://real4x4forums.com/PinzgauerBBS/v ... arb#p51651
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gorsko
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Re: Carb Rebuild - Mark in metal question

Post by gorsko »

Are we looking at the idle bypass drillings or something more sinister? Still can't tell from the shots...
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one2many
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Re: Carb Rebuild - Mark in metal question

Post by one2many »

Gorsko,
No I think they are referring to what I'd call "mixture screws" ....the two screws near the base of each carb have been overtightened and punched their way through the carb body. Quite incredible to see that level of damage and hard to believe someone would exert that much force when working on a carburettor!

I agree with TechMOG......WOW!!!

Oilcan: I'm not sure exactly what I'd do either but perhaps "JB weld" or some other epoxy based product carefully wiped over the damaged areas. Or perhaps Jim.L or EI could have that part of the carb available as used spares.

On the positive side your Pinz should run noticeably better once fixed.

Good luck with it.
1985 pinzgauer 712K factory 2.7lt civilian (RHD, 4 door K)
1979 Volvo tgb 1314a (under construction to om606 diesel/722.6 trans. Dual cab/tray)
oilcan
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Re: Carb Rebuild - Mark in metal question

Post by oilcan »

TechMOGogy - WOW is right. My first thought when i realized was "How soft are these carbs? Whats to keep me from cranking the screws right thru whatever i put over the opening?"
For a bunch of reasons i don't think that would actually happen. I'm surprised the idle mix screws didn't strip, for the amount of torque that would be needed to cause the holes to re-threaded and punch thru the inside like that. Perhaps someone had actually re-threaded them, and thats how they got to where they are?

kdiqq - the ends of the screws were shot, dulled down. I don't have a picture handy, but i kept the screws. will try and remember to post one.

Edzz - thats exactly the same problem - i wonder if this is something systematic w/ the inset screws? With the large screws, you couldn't possibly turn them in past where the screw head meets the carb body.

And Gorsko - it's quite sinister. As one2many mentioned, it's the idle screws... they've burrowed to where they shouldn't be.

This definitely explains the richness. I'm going to look into sourcing just that piece of the carb. SwissArmy seems to have them, or has in the past. I'm afraid to introduce an outside element like JB Weld or Gasket maker in there in case it falls off and heads right to the cylinders... Not sure what it would do in there but I'd guess it wouldn't be friendly.

Thanks for all the thoughts.
oilcan
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Re: Carb Rebuild - Mark in metal question

Post by oilcan »

Can someone convince me my fears about where that little scrap of metal that broke off the inside of the throttle body might have gone are baseless? I feel like given the horizontal cylinder lay out, there's a good chance it just passed right thru the combustion chamber... but the nagging part of me says maybe it 1) did some damage while it was in there or b) is still stuck in there, slowly wearing down some esoteric and unsourceable part.

thoughts? thanks
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Jimm391730
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Re: Carb Rebuild - Mark in metal question

Post by Jimm391730 »

...my fears about where that little scrap of metal that broke off the inside of the throttle body might have gone...
If it got caught between the cylinder and piston then it could have scored the cylinder, but aluminum is soft so it is not likely to have done that. Aluminum is also light, so it probably just got blown out the exhaust valve. If a compression test shows good then I would not worry about it; if you keep the truck for many, many years you might eventually want to have the engine rebuilt, so you will have to figure out what needs done then... no point in worrying about what may have already happened, and is past history and old news now...
Jim M.
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Haf-e
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Re: Carb Rebuild - Mark in metal question

Post by Haf-e »

The throttle body section of the carb is cast iron - not aluminum.

That said, I think it would have found its way out fairly quickly and I wouldn't worry about it now.
Haf-e

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oilcan
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Re: Carb Rebuild - Mark in metal question

Post by oilcan »

Thanks Jim and Hafe - that's a combination of just what I wanted to hear.


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