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Gas mileage?


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So I just put a brand new Weber 38/38 carb on my '76. Fired right up and ran awesome for a day or so.

Now it just doesn't seem right. An example...coming into an intersection and making a right or left...obviously you have to slow down considerably...I down shift into second and make the turn. Then the car bucks really bad and makes me shift into first to get going.

Even with the bad carb I was getting around 26-28 miles to a gallon. I filled up today and it was 17 mpg's. I only got 180 miles out of the tank of gas and it was 90% interstate driving at 65 mph.

What type of mileage should I really be seeing? Does it sound like I'm running very rich on a brand new carb?

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I hear ya...I have a 38/38 on my '75 and I did see a big difference in mpg between my 32/36 and the 38/38. I'm considering going back to the 32/36 even though I've just recently got a new block with 9.5 pistons in it just do to the mpg issue. It's a bummer cause prior to this carb install...I remember getting nearly 30 mpg with it was stock with the 32/36 on it. It was great! Good luck with what ever you do decide to do.

Oh...And right now I'm getting about 20 mpg with my 38/38...Power is pretty darn good, so don't get me wrong...And I most definately can be heavy on the foot, but still...The trade off is the mpg.

One more thing...That problem your having with the turning and having to downshift...I'm not having that kind of problem...Good luck.

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Ok....I definitely have better power. So I'm guessing that the gas mileage is going to be the trade off.

Any ideas on why the bogging down on turns...even turning into the driveway, I almost have to come to a stop to shift into first. If I don't go up the driveway in first it will stall. It's a driveway that you can swing into. Not one that you have to go really slow to get into.

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Honestly, I just installed it. I didn't do anything. I just left everything alone and it seemed like all was well.

I do know some about mechanics, but not enough I guess. What do I need to have done? I'll have to send it out to get things adjusted properly. Let me know what you think so the mechanic and I can have an intelligent conversation. Thanks.

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I have a 38 on my Opel GT with a 2.0 engine, 9.5 pistons and a cam. I love it, but it took me a while to dial it in. Here is what I learned:

- float level is very critical. My carb was new, but the float level was too high.

- Jets: I had to use much smaller main jets, I am at 125 now

- Emulsion tubes: many 38 Webers come with the F50, but you will need F66

- The 2 mixture screws on both sides need to be synchronized, and adjusted according to the specs. If they are not within the recommended range, your idle jets are wrong.

As for mileage, I get 18-20 in town, 25-27 on the freeway.


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