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Problem: black smoke from EA71 exhaust


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Most likely cause in my (less than mechanically educated) opinion is that I'm getting too much gasoline (further supported by my getting 16mpg on a good day)

 

The solution? Rebuild or adjust the carburettor? Problem 2: I have no idea how to do that. Can someone please walk me through it? That would be uber awesome.

 

More info: she smokes like a broken diesel at idle, which is very rough (sometimes stalling) but seems to run much better at higher RPMs. I was thinking that my rings were shot and I was getting blowby, but the oil level doesn't seem to go down and I don't see white smoke, plus she ran fine all the way to Arizona and back with only 147K miles.

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Have you tryed adjusting the carb?

 

The first carborator I rebuilt was the one on my 78 Brat. I learned that rebuilding a carborator is easy, getting it to work again is the difficult part. Mine refuses to idle, and is far worse off than before I rebuilt it. I vote buy a new one if that is the problem. It never hurts to try but dont be too disapointed if it doesnt come out perfect.

 

P.S. my MPG is in the low 20s.

 

Brian

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  • 2 weeks later...

The carb float probably needs to be adjusted, or the needle valve is leaking. It could leak if it has something partially stuck in it so it wont seat all the way, or could be worn down. When the rpms go up it uses more fuel than is leaking, so it runs better, when its idleing more fuel is getting fuel than it use, so the carb overflows making it run poor or die.

 

My 85 brat averages 34mpg per tank driving 110 miles per day, I would think a gen 1 would get slightly better.

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Have you tryed adjusting the carb?

 

The first carborator I rebuilt was the one on my 78 Brat. I learned that rebuilding a carborator is easy, getting it to work again is the difficult part. Mine refuses to idle, and is far worse off than before I rebuilt it. I vote buy a new one if that is the problem. It never hurts to try but dont be too disapointed if it doesnt come out perfect.

 

P.S. my MPG is in the low 20s.

 

Brian

 

Wow I was going to say that my bro in law said that he tried to rebuild his carb in his Dodge Dart and said he could never get the stupid thing to run right since so he got mad at it and bought a new one :)

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  • 2 weeks later...

My carb is the hitachi. It doesnt idle, but you get pretty good at feathering the pedal and using the E-brake at stop lights. but my car is so out of tune its laughable.

 

I did a little bit of maintenance on it a while back, reset the valves, and an oil change... while I was at it I bought a jug of "sea foam" and added it to my gas and oil. My dad was going on and on about what a difference it made in his trucks so I figured what the hell. Then the next day on the drive home from work it started smoking really bad on throttle so I pulled the number four plug and it was covered in black goo. So I replaced all the plugs and let it sit in my garage, starting it up once or twice a week. I took the Brat out today, and it actually idled. I was amazed. Doesnt cold idle, but at stoplights it actually stays running. I am thinking aside from the being horribly tuned, my engine was just VERY dirty. You'd be amazed how much a little gunk will mess up a carborator.

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