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Black soot from exhaust ever since I added 38/38....

Guest Anonymous

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Guest Anonymous

URL: http://members.aol.com/_ht_a/ths916m3/myhomepage/profile.html?mtbrand=AOL_US

I need some assistance regarding my Weber 38/38. It seems like its not performing up to my expectations, maybe its not tuned right yet. It does start a whole lot better than the solex did, but it doesnt seem to have a lot of extra get up and go. There is a lot of black soot that comes out of the exhaust that was never close to that bad. Also, I think I might be slowly killing myself by all the fumes that my car seems to be putting out. Any help is greatly appreciated....Oh and Frank if you read this I tried putting on the idle control valve and it doesnt fit, the assembly for the water choke is in the way. Any help on this is appreciated as well, but I can live with a slightly rough idle.


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Guest Anonymous

Is it new?

Make sure the choke is not stuck closed.

Find out what the jetting is.

Mine came from Maximillian with:

45 idle

142 main

185 air corr.

This is on a 140K mile original '76 motor.

I upped the idle jets to 50 and it helped the local lower RPM driving. It really shines on the highway.

It'll run a little rich since its really too much carb for the stock motor, but it shouldn't be as bad as you describe.

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Guest Anonymous

If you can see noticable black sooty smoke and smell the exhaust, it's running REALLY rich - whatever is causing the over-rich condition, it needs to be resolved as soon as possible.

Most likely culprit is the choke and/or (less likely) the idle mixture - if you have a water choke carb, you'll need to make sure coolant is getting to the choke and back to the engine, then run the engine until it's warm and pull the top off the air cleaner and make sure the choke is opening fully. If enough coolant is NOT getting to the carb to heat the choke and open it, you'll need to either find out why and fix the problem or adjust the choke so it's always open until you find out why. If it's a electric choke unit, hook the terminal on the choke coil directly to the hot side of the battery with a jumper wire and make sure the choke opens all the way (mine didn't when I first got it).

The initial adjustment on the idle mixture screws should be somewhere around 2 turns out - make the initial adjustment by turning both screws in all the way, then back them out about 2 full turns.

It's also possible that your float height is off (or the fuel pressure is too high if you're running an electric pump) - in either case you might be getting too much fuel past the float bowl.

When I got my 38 from Ireland almost 2 years ago, I went through several rounds of jet changes to get it right, but once it was dialed in, the engine (dead stock with 140K miles on it) picked up at least 10-15 hp and mileage improved by about 15-20% over the single bbl Solex.

I'm in the Sacto area as well - if I can be of further help e-mail me off line and I'll do my best to assist....

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