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aircobra

Clouds Of Smoke Behind The Car - Why?

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i was driving at night for the first time ( new rebuilt L24) and noticed that at past 3000 rpm, I'm getting an awful lot of what looks like badly combusted gasses billowing from the exhaust.

It is NOT oil, as it doesn't have the blue tinge or smell, but more grey/back

Checked the timing with strobe and its spot on

When I pulled the plugs, they're really black ( but not oily), which leads me to conclude that i'm running way too rich.

The car runs fine otherwise and has plenty of power

i know that there are threads on setting the float levels and the mixture knobs, so I set them knobs to default 2 turns

http://www.teglerizer.com/sucarbs/techtip6.htm

is there someone in SE Melb suburbs with a C02 analyser

 

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I don’t understand where these questions are coming from of late.

There is no set number of turns on a mixture adjusting screw to provide a perfect mixture / idle, only a guide as to a starting point. I think the 240z round top hitachis starting point is about 2.5 turns or there abouts.

Every car and carb is different depending on the enormous range of variables that an engine and environment can have.

 

I suggest you have your car run up on a dyno to tune the air/fuel ratio that suits your engine.

With regards to your hitachis, your tuner will select the appropriate tapered needles and springs.

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Cozza.

           Well said and spot on. Mixture adjusting screws for idle. If you don't have the correct needles for your engine, it can never be perfect.

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i don;t have a private tuner person or a dyno - just me

anyway, took the tops of the float chamber and found that the gap on the rear carb was too small  eg too much fuel in the chamber. this looks like the primary cause at this stage. reset to1.4cm from float to surface, blowing air thru the inlet for a reference point on valve close

also found some petrol residue around the knob which i think its been leaking over the top of the mixture tube

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Call Richie at Allcraft Automotives in Moorabbin - he'll tune it up for you.

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 found that the gap on the rear carb was too small  eg too much fuel in the chamber.

 

 

also found some petrol residue around the knob which i think its been leaking over the top of the mixture tube

 

First point will potentially cause the second, if fuel level in float chamber is too high, fuel will be too hig in the jet tube and may flow over the top of the tube, run down between tube and carb body and end up on various bits underneath the carb.

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How about a book from airacobra titled 'The Complete Daily World Involving Zed Fault Experience', subtitled, 'Saved by the Intrawebs on a Daily Basis', sub subtitled 'Tips on Having Zed Problems'.

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to all helpful top blokes on the thread, here's the update

took to ritche, he kept the car for a day, ran it up on the dyno and diagnosed bent/worn needles.

with my wallet $600 lighter, and the needles replaced runs much , much better.

so high 5 to lurch for the tip

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