Rich and famous

[f1fascination]

Hi all, probably and area that has been well explored previous, but after rebuilding (Kitting) and setting the balance and idle of my Dellorto's, the car run's massively rich, to the point she fouls her plugs if left idling for too long.
The idle is beautiful and smooth before that happens however, and the engine accelerated without too much hesitation. I though perhaps the idle jets may be too big, but they are standard.
Is there a way to lean her out, or must I bite the bullet and get her tuned by a "professional"?
I'm quite proud of the fact that I'm restoring this car all by myself, and wish only to leave paint and trim to the guru's.
The cylinder head and valve gear are new, and the head was re-conned with reground cams, but all standard.

[colcol]

Have a look at your spark plugs, and make sure they are of the correct heat range, if they are too cold, they won't be getting hot enough to fire and to burn all the crap off the plugs.
If you can, make sure the 'standard' jets haven't been drilled out, say it states that the jets have 0,3 mm stamped on them, that someone hasn't drilled them for 'more power'.
A way to try and work out what a good size for the jet is to either drill it out for more fuel or solder up the jets and drill them out to a smaller size for less fuel, but thats best left to someone with a dyno or engine C.O. capabilitys, Colin.

[f1fascination]

Thanks Col, the plugs are also standard B7ES's, but maybe I should step them up to the next heat heat range just as a test.
I'll check out those jest again too.
Cheers!

[colcol]

You are welcome to come to the 105 technical night at Maranello Pursang Motors at 33 Colebrook street, Brunswick on August the 8th at 6-30 pm, you could ask about spark plug heat ranges and jets on Dellorto's, just a hop skip and a jump from Western Australia to Melbourne, Colin.

[f1fascination]

Ha ha!, unfortunately my travel budget for the year is bust after a trip to Tassie for the Targa this year.
I'm going to throw a set of plugs in her first and go from there, but I'll let you know how I get on
Thanks for the invite though...

[105gta]

Spuds like the float levels are out of whack. If you replaced the needle and seats then they have to be reset.
Ben

[MD]

to the point she fouls her plugs if left idling for too long.

The 7 plug is too cold.

For a standard 105 street engine the heat range spark plug BP6ES has been used predominately.

[f1fascination]

Spuds like the float levels are out of whack. If you replaced the needle and seats then they have to be reset.
Ben

Checked and double checked the float levels and mixture needles, the balance is perfect so I'm going up a heat range in plugs (lower number) as per..

to the point she fouls her plugs if left idling for too long.

The 7 plug is too cold.

For a standard 105 street engine the heat range spark plug BP6ES has been used predominately.

.. and give that a bash.
Many thanks folks!

[f1fascination]

Ran a new set of BP6ES plugs through and she still turns them black pretty quick.
Smokes fairly well while free-revving her in neutral too, and bit of a haze shows out the tailpipe while idling too.
I'm going to whip out the jets next and check them again, to make sure they haven't been drilled out by someone chasing more fuel.

[MD]

Faark that's disappointing.
You got multiple problems.
Might find some good help here: http://sideways-technologies.co.uk/forums/index.php/topic/1048-setting-dhla-dellorto-dellorto-float-fuel-level/

Personally I would try no more than 2 PSI fuel pressure. Also get some confirmation on the intensity of your high tension spark. You also need a an exhaust gas analyser to see what's happening to your combustion.
Oil smoke suggest a tried engine and white smoke that you have a head gasket water leak.

I know it's not what you want to hear but I am starting to think you need to head for some quality trade (read paid) help.

[f1fascination]

Thanks MD, engine is only showing black smoke, not blue, or white.
Head is new, fuel system is new, leads, plugs, cap, rotor points, all new.
I'll have another shot at setting the floats though, but I would have expected fule to be dribbling out the vent cover if the level was too high.
Thanks!

[MD]

OK that's clarified some of your engine symptoms.

Two things stand out:-

1 You haven't told us your actual fuel pressure.
2 We don't know the quality of your high tension spark.

Having new leads etc is only half the story. All well and good having a satisfactory delivery system for the spark generated. However if the quality of the spark itself is poor, it isn't going to get better just because it has a good delivery parts set. The old addage: you put sheit in, you get sheit out. Coils can and do go bad. Primary windings can get insufficient current and voltage and still work but produce week high tension and fire the motor. How sure are you that the coil is getting a good quality B+ feed ?

Likewise too much fuel pressure will stuff up your mixtures and doesn't matter what jets you got in there. I say again, confirm you have 1.5 >2.0 psi by borrowing a master pressure gauge if you have to.

Do not simply assume that in both these cases it's "right".

[f1fascination]

Thanks MD, I can tell you a bit more. The coil is not new, though it's resistance measures OK, it probably want's replacing.
The leads and the rest of the ignition system are all new items from Classic Alfa, so I have to assume they are alright.
The mechanical fuel pump is a new item from Classic Alfa also, though I have fitted an additional in-line filter beside it. I wouldn't have thought I had a high fuel pressure fault with that as it is original spec.
The original filter in it's glass bowl is also new.
I have fitted the carbs with new needles and seats, etc, again, more parts straight from my favourite Alfa parts supplier.
I rebuilt and tuned them as per "How to power tune Weber and Dell'orto carburettors", using their method of setting idle and balance, etc.
The idle screw adjustments fall within the range specified in the book, approx 3 and 1/2 turns out from fully closed.
The engine starts and idles nicely, with a little choke from cold, but as I've said, turns the plugs black quickly and puffs smoke at idle.
I appreciate all the feedback from you guys, I'll check a few more bits and pieces when I get back from work.