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All-right well the previous owner took something out and I cant seem to find what it is in the manuals, I'm gonna grab it the next time I go to the junkyard, I'm assuming it has to do with emissions. What attached to the bowl shaped metal piece to the right in this picture and what is its function? Thanks.

 

n846795391_5051069_4761.jpg

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Ah sorry EA81, Yeah...I have to turn the fan on with a switch inside the car...it has a bigger radiator and single fan in it, courtesy of the previous owner, so I guess I shouldn't bother getting that unless I want to get my fan to turn on automatically. I'm more worried with emissions... there are several vacuum lines missing from the air filter housing I'll have to see where they go to on the junked EA81.

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That is, was, the vacuum diaphram that opens the secondary venturi on the carb. When you open the throttle, part way, a third I think, the linkage starts to open the second barrel. When it opens it creates a vacuum signal in that venturi that draws on that diaphram that is attached to the secondary venturi and opens it up according to the strength of the vacuum signal.

In short, it opens the second barrel on the carb. If there is no cobbed up linkage to open the second barrel mechanically, that engine will be weak operating off of one barrel.

Sounds like you need to take a good look around the car to see what else you have to fix......

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hmmm, well the previous owner said that he did the mod to get the second barrel to open early, I looked at the guide for it, and then the engine, and couldn't see any mod like that done, however i could be wrong because the thing is so dirty... I guess what i have to do is have some one step on the gas while I look inside the carb...haha

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Next time you drive the car, try to go from a rolling start and then stomp on it. If you get a huge dead spot, then the car goes like stink.. chances are it has the mod done.

 

The secondary mod forces the second barrel to open when throttle gets past 3/4 to WOT. However, usually the second barrel isnt primed and you get a lean condition before it forces fuel through... this is what causes a dead spot in the acceleration. But after that, its usually noticable.

 

It's hard to see if the mod was performed if the vacuum diaphram is still attatched. It blocks the linkage and makes it hard to see.

 

Here's a small write-up I did on the mod:

http://4lug.bydemons.com/index.php?view=items&cid=1%3Amods&id=3%3Amodified-hitachi-2bbl-carburator-ea81&option=com_quickfaq&Itemid=6

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I guess what i have to do is have some one step on the gas while I look inside the carb...haha

 

Step away from the carb, please. :)

 

If you really wanna...take a cable, a return spring, and a small parts kit.

 

Hook it all up. Leave that vacume thingy off.

 

Wala. Mechanical secondary.

 

Doug

 

Never mind.

Edited by Quidam
Never mind.
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Even if the PO did that mod there should still be the diaphram on that as well as the cover because you have a vacuum leak without it. There is a pinhole vacuum point on the outer edge of that bowl (at least there was on my former hitachi.

 

As for finding out if the mod was done, with the car off look down the carb and manually open up the throttle. If both barrels open up the mod was done. If not, get a cover and a new diaphram and go to work.

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Thanks for all the advice guys! I'll check it out when I get home from the college this weekend! Great write up subarujunkie, I will probably revert it back to factory specs cause I'm worried about NJ emissions tests and fuel milage more than power haha, assuming the mod was done..

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Even if the PO did that mod there should still be the diaphram on that as well as the cover because you have a vacuum leak without it. There is a pinhole vacuum point on the outer edge of that bowl (at least there was on my former hitachi.

 

As for finding out if the mod was done, with the car off look down the carb and manually open up the throttle. If both barrels open up the mod was done. If not, get a cover and a new diaphram and go to work.

 

 

Yeah there is a hole on the side of the carb that supplies vacuum or pressure to the diaphram. I plugged it with a screw when I did my mod.

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