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914World.com _ 914World Garage _ idf a/f idle mixture needle screws

Posted by: rhodyguy Jun 30 2006, 10:02 AM

still chasing it. i replaced the the mallory cap and rotor.

1. persistant rough idle.
2. loss of power while climbing grades.
3. when i turn the screws in on the 1/2 cyl carb the idle quality change is not as appearent as the other carb.
4. coming to a stop the idle will fall way down and slowy pick up.

the newer looking one is on the left ( out of one of the 44s i have) and the one on the right is the style currently in the car. very obvious design difference. o ring sealing the screws are flattend out and look suspicious.

does anyone know if the port design was changed during production? will the "newer" needle work as a replacement of the "old" style, or just swap out the the o-ring? old ring is on the left. my thought is a defective ring would let air sneak through giving an inacurate adj on the mixture

plug pict is of one from the "bad" side of the engine and has about 500 miles on it. electrode is clean, color seems about right, so i think the "spark" is not an issue.

thoughts?

k

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Posted by: SirAndy Jun 30 2006, 12:43 PM

don't know the answer but i'll give this a ...

i had to buy extra o-rings for my 44 IDFs as the rebuild kit didn't have enough ...
Andy

Posted by: lapuwali Jun 30 2006, 01:03 PM

The long, tapered screws are, IMHO, the "good" screws to use. They actually allow some adjustment. The newer stepped screws are basically on/off.

Posted by: rhodyguy Jun 30 2006, 01:59 PM

spark you could weld steel with on the bad carb side. blew out the jets, and circuit. idle a/f needle valves no effect on one barrel and minimal effect on the one next to it. i took them to Carbs Unlimited (local firm) they'll be ready on monday.

i can't complain. they were on an engine in total i bought in late 02'. cleaned up the engine, put it in the car and i've been driving it since. italian made 40s.

k